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LIBRARY 

OF THE 

University of North (Carolina 

Endowed by the Dialectic and Philanthropic- 
Societies. 



Call No. 



UNIVERSITY OF NIC. AT CHAPEL HILL 



00010361636 




:..-,.. s« 



^-^WjAA^4jZi 



U 






OF 



QUANTITATIVE CHEMICAL ANALYSIS 



FOR THE USE OF STUDENTS. 



BY 



FREDERICK A. CAIRNS, A. M. ; 

INSTRUCTOR IN ANALYTICAL CHEMISTRY SCHOOL OF 
MINES, COLUMBIA COLLEGE. 



NEW EDITION. REVISED AND EDITED BY 
E. WALLBE, Fh.D., 

INSTRUCTOR IN ANALYTICAL CHEMISTRY IN SCHOOL OF MINES. 




Qb/Q/ 



&A0 , 



NEW YORK 

HENRY HOLT AND CC 

1888 




*Af£i. 



Copyright, 1830, 
By MART SNOWDEN CAIKN8. 



TO 



PROFESSOR CHARLES F. CHANDLER, 

THE FRIEND, TEACHER, AND CO-LABORER OF THE 

AUTHOR, THIS BOOK IS, IN ACCORDANCE 

WITH THE AUTHOR'S 

WISHES. 

DEDICATE!}. 




^0 

•Os. 



NOTE BY THE EDITOR. 



Mr. F. A. Cairns, the author of this work, died sud- 
denly while engaged in preparing the first edition for the 
press. 

The undersigned completed what was found to be 
necessary, and the work was published. 

After using it in class room and laboratory for a year, 
it has been deemed advisable to prepare and issue a new 
edition in which a few typographical errors have been 
corrected and some notes of an explanatory nature added. 
In a few cases it has also been found preferable to modify 
the phraseology employed, and a new chapter has been 
added on the testing of illuminating gas. 

It is to be hoped that the changes made will meet with 
the approval of those making use of the book, and that 
the conscientious labors of the author will still have the 
cordial appreciation of workers in this branch of chemistry. 

E. Waller. 

« 



• 



AUTHOR'S PREFACE. 



This little manual is designed to assist beginners in the practice 
of quantitative analytical chemistry. 

The aim is, by explaining some of the more serious obstacles to 
successful analysis, to teach thoughtfulness and caution, and by 
giving very explicit directions in the earlier part of the course, to 
induce habits of precision, and impart a sufficient amount of 
knowledge of chemical manipulation to enable the student to pro- 
ceed without further leading. 

The system adopted is to teach at first the determination, indi- 
vidually, of the constituents of compounds, composed of elements 
which will afterward, very frequently, be found variously asso- 
ciated, particularly in mineral analysis ; and then to teach the 
quantitative separation of these elements, in the analysis of com- 
pounds containing a number of them ; advancing, step by step, 
from the analysis of compounds of similar character to the 
analysis of more complicated ones, involving a knowledge and 
application of what has preceded. 

In addition to the series of what may be called strictly mineral, 
have been added a number of analyses of substances of an organic 
character, found in commerce, which will give the student an 
insight into the work which will probably be required of him as a 
practical chemist. 

The range of these is necessarily restricted, as it is desired to 
keep the work within the limits of a simple hand-book. 

The writer has avoided giving numerous methods of analysis of 
the same substance, but has selected those which he knows to be 
good, and which he believes to be the best. 

The instructor is expected to enlarge upon the instructions 
given here, and the student to study other works of a more 
elaborate character. Success requires knowledge of theoretical 
chemistry and quantitative analysis. 



REFERENCES. 



The references are to : 
' ' Fres. , Qual. Anal. " — 

Fresenius's Manual of Qualitative Analysis. Translated into the new 
system. Edited by S. W. Johnson. New York : 1875. 
u, Fres., Quant. Anal.''' 1 — 

Quantitative Chemical Analysis. By Dr. C. R. Fresenius. Edited by 
S W. Johnson. New York : 1871. 
'H. Rose, Quant. Anal.'''' — 

Traite Complet de Chimie Analytique, par M. Henri Rose. Edition 
Francaise originate, Analyse Quantitative. Paris : 1862. 



TABLE OE CONTENTS. 



Chapter. Pa0K : 

Introduction ■ L 

I. — Barium Chloride • ■ • • *■* 

II. — Magnesium Sulphate. 17 

III.— Calcium Carbonate. . . . . . 20 

IV. — Potassium Alum . . 26 

Y. — Calcium Fluoride 31 

VI. — Potassium Iodide 34 

VII. — Potassium Bromide 35 

VIII.— Hydro-Disodium Phosphate 36 

IX. — Ammonio-Ferric Sulphate, or Ammonia Iron Alum 40 

X.— Feldspar........ 49 

XI. — Limestone. ....... 59 

XH.r-Clay.... ........ ............ .......................... G7 

XIII.— Manganese Ore ........ . 70 

XIV. — Partial Analysis of Iron Ore. 78 

XV. — Complete Analysis of Iron Ore.. 86 

XVI.— Slag. .. . 100 

XVII.— Cast-Iron, Steel, and Wrought-Iron 102 

XVIII.— Zinc Ore = ................. 123 

XIX.— Nickel Ore ............ . ........................ .... 127 

XX.— Copper Ore. .................*.... .v. .................. 136 

XXI.— German Silver ............. . . . . s . . . . . ... . . . ............. 140 

XXIL— Galena.............. ...........:................*.. ... 142 

XXIII.— Tin Ore 145 

XXIV.— Bronze. .. . 147 

XXV.— Arsenic Ore 149 

XXVI,— Antimony Ore 152 

XXVII.— Type Metal 154 

XXVIII.— Refined Lead 157 

XXIX.— White Paint Ground in Oil 167 

XXX.— Fresh Water 173 

XXXI.— Mineral Water 184 

XXXII.— Superphosphate of Lime.. .197 

XXXIII.— Milk , ., 204 

XXXIV. — Acidimetry and Alkalimetry 207 

XXXV. — Commercial Bicarbonate of Soda 215 



yiii CONTENTS . 

Chapter . Page. 

XXXVL— Chlorimetry 218 

XXXVII.— Acetate of Lime 221 

XXXVIII.— Guano 223 

XXXIX.— Raw Sugar 226 

XL. — Sugar (Ultimate Analysis) 231 

XLL— Turpentine (Ultimate Analysis) 233 

XLIL— Bone-Black .234 

XLIII.-Coal 238 

XLIV.— Petroleum 242 

XLV, — Examination of Illuminating Gas. . . 245 

XLVI. -Soap . . . . 252 

XL VII.— Flour ...... 255 

TABLES. 

Comparison of French and U. S. Weights and Measures « 262 

Atomic Weights 263 

Specific Gravities and Degrees Beaume. . , . 264, 265 

Strength of Sulphuric Acid 265 

" " Hydrochloric Acid 265 

" " Nitric Acid 267 

1 < Tartaric Acid 23S 

" Citric Acid 268 

"Acetic Acid 269 

" "'Ammonia 269 

" Potash Lye 270 

■« " Soda Lye 270 

" " Sodium Chloride ... 271 

Si " Ammonium Chloride 27 1 



INTRODUCTION". 



As gravimetric analysis is effected by separating, one by 
one, the different constituents from a solution containing 
a known amount of the substance to be analyzed by adding 
other substances, called reagents, which will form with the 
constituents to be determined compounds insoluble in the 
surrounding fluid, care must be taken not to use excessive 
quantities of these reagents. 

Take, as an illustration, the analysis of limestone. After 
decomposing the stone and separating the silica, which is 
done in acid solution, the solution is made alkaline with 
ammonia, by which means the ferric and aluminic hy- 
drates, being insoluble in ammonia, are precipitated ; the 
lime is then precipitated, by the addition of ammonium 
oxalate, m calcium oxalate, a compound insoluble in am- 
monia ; the magnesia is then precipitated from the residual 
fluid as magnesium ammonium phosphate (by the addition 
of sodium phosphate), a compound insoluble in ammonia. 

This is the outline of the method of analysis. Suppose 
an excessive quantity of hydrochloric acid to have been 
used in the flrst instance, a large quantity of ammonia 
would be required to precipitate the iron and alumina, and 
consequently a large quantity of ammonium chloride formed 
in the solution. If, in addition to this, an unnecessary 
quantity of ammonium oxalate were used, it would be 
found impossible to complete the analysis successfully 



M INTRODUCTION. 

without danger of loss and great waste of time and labor. 
The danger of loss al ways accompanies prolonged operations 
in chemistry ; the waste of time would be consequent upon 
the necessity of evaporating to dryness to expel the large 
amount of ammonium chloride, in the presence of which 
the magnesium could not be completely precipitated (an 
operation involving considerable loss of time and possibly 
of substance). Finally, after all this waste of time and 
labor, the presence of other salts, not volatilized by heat, 
would render it impossible to concentrate the fluid to the 
proper point for the thorough precipitation of the mag- 
nesium as phosphate, it being somewhat soluble in large 
amounts of fluid. Such difficulties as these can in nearly 
all cases be avoided by using no more of a solvent (acid or 
alkaline) than is necessary, and no more of a precipitant 
than is required to effect complete precipitation, or, in 
other words, by avoiding excessive use of reagents in all 
cases. 

A knowledge of the use of solvents can be attained by 
studying the solubility of substances, and a knowledge of 
the amount of reagents to be used by simple stoichiomet- 
rical calculations. The student should bear in mind that 
water is also a reagent, and that excessive use of it is to be 
condemned. At the end of this chapter will be found a 
table giving the amount of the different elements, etc., 
precipitated by 1 c. c. of a solution of each of the reagents 
most commonly used. 

Before beginning an analysis of any complexity, a plan 
should be adopted and well studied. In many cases, tabular 
schemes will be found very useful, as they enable the 
chemist to see at a glance the relative bearing of each part 
of an analysis, and refresh the memory without loss of time. 

MEASURING. 

This requires vessels of various kinds, the capacity of 
which is known, such as flasks, pipettes, burettes, etc. 






• MEASURING. 3 

Flasks. — Of these it is well to have a series which will 
deliver respectively 50 c. a, 100 c. c, 150 c. c, 200 c. a, 
250 c. c, 300 c. c.j 500 c. c, and 1000 c. c. In most cases, 
it is not of so mnch importance that they should be ab- 
solutely accurate as to capacity, as that they should bear 
an accurate relationship to each other, as otherwise it will 
be impossible to divide solutions correctly, a matter of the 
greatest importance in quantitative analysis. If it is desired 
to standardize a flask with great precision, it can be done 
by counterpoisirg it on a balance with any kind of weight 
that is convenient, adding weights to those on the balance 
to an amount corresponding to the capacity of the flask, 
adding the proper amount of water, and marking the neck 
of the flask. As an illustration, we will suppose that it is 
desired to prepare a 50 c. c. flask. Select a flask with a 
narrow neck, in which the water will rise about half-way, 
upon introducing about 50 c. c. of it ; dry the flask thor- 
oughly, inside and out, place it upon the pan of a balance, 
counterpoise it with any convenient weight, add to the 
weight 49.9405 gms., and introduce into the flask distilled 
water of 16° C, until perfect equilibrium is produced 
(after drying the neck of the flask above the water-line). 
Then mark the neck of the flask, which must stand perfectly 
level, where it is intersected by the horizontal plane coin- 
ciding with the bottom of the meniscus. This mark is what 
is called the ' ' holding " or " containing ' ' mark. Of course, 
when the contents of the flask are poured out, some of the 
fluid will adhere to the sides, and it will fail to deliver 50 
c. c. It becomes necessary, therefore, to establish a point 
to which the flask must be filled to enable it to deliver 50 
c. c. To do this, fill the flask with water, empty it, counter- 
poise it as before, together with the fluid adhering to the 
inside, being careful that the outside is dry, replace the 
weights amounting to 49.9405 gms., introduce distilled 
water of 16° C. until equilibrium is restored as before, 
and mark the neck of the flask where it is intersected 
by the horizontal plane tangent to the bottom of the 



4 INTRODUCTION. 

meniscus. This mark is what is called the "delivery'* 
mark. 

In this way, all the flasks required can be prepared with 
great accuracy. If, however, an accurately measured flask 
is at hand, another of twice or thrice the capacity can 
readily be prepared by filling the smaller flask to the deliv- 
ery mark with water of 16° C, emptying it into the larger 
flask, previously dried, repeating until the desired volume 
is reached, and marking upon the neck of the flask the 
holding point. By repeating the operation upon the wet 
flask, the delivery mark can be established. 

Flasks can also be prepared with great ease by means 
of a pipette the capacity of which is known. If, for instance, 
a, pipette which is known to deliver 50 c. c. is at hand, 
all that is necessary to prepare a 200 c. c. flask is to dry 
it, run into it 4 pipette-fulls of water of 16° C, and mark 
the proper point on the neck as the holding mark ; and 
determine the delivery mark by repeating on the wet flask. 

Pipettes. — These can usually be purchased cheaply, so 
that ordinarily there is no occasion to make or graduate 
them. Their accuracy should, however, always be verified. 
This is commonly done by filling them up to the proper 
mark with water of 16° C, running this water into a 
weighed flask, and weighing the amount delivered. This 
should be nearly the same number of grammes as the 
pipette is supposed to contain in cubic centimetres, a slight 
difference being made for the expansion of water between 
and 16° C. One cubic centimetre # of water at 16° C. 
weighs 0.9988 gms. 

A pipette must always be filled by suction to above the 
mark, with the liquid to be measured ; then, by closing the 
top with the dry finger, the liquid may be allowed to run 
slowly out, until the lower part of the meniscus is at the 
line. It will then (if correct) deliver the number of c. c. 
marked upon it. Pipettes being used for delivery only, 
have no holding mark, as with flasks. In running the 
liquid out of the pipette, touch the tip lightly against the 



WEIGHING. O 

side of the vessel into which it is delivering, until no more 
runs out. Never blow out the last drop, since that ren- 
ders the measurement inaccurate. 

If a burette is taken, the accuracy of which has been 
verified by weighing the amounts delivered, as referred to 
above, the accuracy of any number of pipettes may be 
readily tested, by first filling them with water, running it 
out so as to leave the same amount adhering to the glass 
as when in use, and then closing the tip with the finger, 
and running in water of 16° C. from the burette. For 
this work, the burette should be provided with a fine- 
pointed delivery -jet. 

The same method will serve for graduation, if that is 
necessary. (See Thorpe's " Quant. Anal." pp. 112 et 
seq.) Students should also have a few small test glasses 
holding from 10 to 15 c. c, and graduated to c. c. These 
will be found more convenient for controlling the use of 
reagents than pipettes, and for most purposes are suf- 
ficiently accurate. 

For measuring of gases, read Fresenius, who extracts 
from the best authorities, such as Bunsen, Eegnault, and 
others. 

WEIGHING. 

As quantitative analysis requires, in addition to the sep- 
aration of the constituents of a substance, the determina- 
tion of their relative quantity, accurate weighing is abso- 
lutely necessary. A good balance is, of course, essential. 
For discussions of the principles of the balance, the student 
is referred to such works as that of Fresenius, as space will 
not allow their being introduced here. Rules for weigh- 
ing are all that are admissible. Those given by Fresenius 
are introduced here. 

1. The safest and most expeditious way of ascertaining 
the exact weight of a substance is to avoid trying weights 
at random ; instead of this, a strictly systematic course 
ought to be pursued in counterpoising substances on the 



6 INTRODUCTION. 

balance. Suppose, for instance, we want to weigh, a cru- 
cible, the weight of which subsequently turns out to be 
6.627 gms. ; we place 10 gms. on the other scale against 
it, and we find this too much ; we place the weight next 
in succession, i. e., 5 gms., and find this too little ; 
next 7, too much ; 6, too little ; 6.5, too little ; 6.7, too 
much ; 6.6, too little ; 6.65, too much ; 6.62, too little ; 6.63, 
too much; 6.625, too little ; 6.627, right. 

I have selected here, for the sake of illustration, a most 
complicated case ; but I can assure the student of quanti- 
tative analysis that this systematic way of laying on the 
weights will, in most instances, lead to the desired end in 
half the time required when weights are tried at random. 
After a little practice, a few minutes will suffice to ascer- 
tain the weight of a substance to within the tenth of a 
milligramme, provided the balance does not oscillate too 
slowly. 

2. The milligrammes and fractions of milligrammes are 
determined by a centigramme rider (to be placed on or be- 
tween the divisions on the beam) far more expeditiously 
and conveniently than by the use of the weights them- 
selves, and at the same time with equal accuracy. 

3. Particular care and attention should be bestowed on 
entering the weights in the book. The best way is to 
write down the weights first by reference to the blanks or 
gaps in the weight-box, and to control the entry subse- 
quently by removing the weights from the scale, and re- 
placing them in their respective compartments in the box. 
The student should, from the commencement, make it a 
rule to enter the number to be deducted in the lower line ; 
thus, in the upper line, the weight of the crucible + ^ ne 
substance ; in the lower line, the weight of the empty cru- 
cible. 

4. The balance ought to be arrested every time any 
change is contemplated, such, as removing weights, substi- 
tuting one weight for another, etc., etc., or it will soon be 
spoiled. 



WEIGHING. 7 

5. Substances (except, perhaps, pieces of metal, or some 
other bodies of the kind) must never be placed directly 
upon the scales, but oYight to be weighed in appropriate 
vessels of platinum, silver, glass, porcelain, etc., never on 
paper or card, since these, being liable to attract moisture, 
are apt to alter in weight. The most common method is 
to weigh, in the first instance, the vessel by itself, and to 
introduce subsequently the substance into it ; to weigh 
again, and subtract the former weight from the latter. In 
many instances, and more especially where several portions 
of the same substance are to be weighed, the united weight 
of the vessel and of its contents is first ascertained ; a 
portion of the contents is then shaken out, and the vessel 
weighed again, the loss of weight expresses the amount of 
the portion taken out of the vessel. ' 

6. Substances liable, to attract moisture from the air 
must be weighed invariably in closed vessels (in covered 
crucibles, for instance, or between two watch-glasses, or 
in a closed glass tube) ; fluids are to be weighed in small 
bottles with glass stoppers. 

7. A vessel ought never to be weighed while warm, 
since it will in that case invariably weigh lighter than it 
really is. This is owing to two circumstances. In the first 
place, every body condenses upon its surface a certain 
amount of air and moisture, the quantity of which depends 
upon the temperature and hygroscopic state of air, and 
likewise on its own temperature. Now, suppose a crucible 
has been weighed cold at the commencement of the oper- 
ation, and is subsequently weighed again while hot, together 
with the substance it contains, and the weight of which we 
wish to determine. If we subtract, for this purpose, the 
weight of the cold crucible, ascertained in the former 
instance, from the weight found in the latter, we shall 
subtract too much, and consequently we shall set down 
less than the real weight of the substance. In the second, 
place, bodies at a high temperature are constantly com- 
municating heat to the air immediately around them ; the 



8 INTRODUCTION. 

heated air expands and ascends, and the denser and colder 
air, flowing toward the space which the former leaves, pro- 
duces a current which tends to raise the scale-pan, making 
it thus appear lighter than it really is. 



FILTERING AND BEAKEES, ETC., WASHING-. 

Lipped beakers are always preferable. In pouring from 
a beaker, the stream should be always poured against a 
glass rod. No grease is required on the under side of the 
lip, if it is properly formed. The under side of the lip 
should always be dry. Rubbers on the rods should only 
be used to clean vessels. In filtering, the rods should 
have no rubbers on them, as it may introduce organic 
matter into the solutions, which may cause error in the 
work. 

When a vessel holding several litres is to be heated, as 
it may be fractured by the great weight of fluid, if the 
bottom rests unevenly upon its support in heating, sand 
may be used as a support. In other cases, the use of sand 
is objectionable. It requires a longer time to heat a vessel 
standing upon sand, and the sand is very liable to adhere 
to the bottom of the vessel, and from it drop into the 
analysis. 

In filtering, the filter should always be accurately fitted 
to the funnel, and the funnel adapted to the size of the 
filter, always using the smallest filter that will allow a 
proper washing of the contents. The larger the filter, the 
more washing it requires, and the greater the liability to 
error in allowing for the weight of the ash. 

Corrugated filters should never be used in quantitative 
work, where the precipitate is to be weighed, as it is very 
difficult to wash them properly, and it is very difficult to 
remove the precipitate from them, which is often neces- 
sary. 

In washing, allow all the solution to run through the 



FILTERING AND BEAKERS, ETC., WASHING. 9 

filter, before adding any water, then fill up the filter with 
water, and allow that to run through before adding more. 
By this means, excessive quantities of wash-water may be 
avoided. In washing by decantation, which is necessary 
with some precipitates, the same principle is used. Allow 
the precipitate to settle, decant as closely as possible, 
pouring the liquid through the filter, add water, stir well, 
let settle, and decant again closely before adding more 

wash-water. 

Crucibles and Ignition. — Crucibles should always have 
covers and be cooled and weighed with them on, to avoid 
loss of substance and to exclude dust, etc. 

Previous to ignition, the filters and contents must be 
thoroughly dried; on ignition, the paper t must be thor- 
oughly consumed, so that no carbon remains. Heat gently 
at first, so as to carbonize the filter without flame, and 
afterward intensely. The destruction of the filter-paper 
is most readily effected by tilting the crucible, and finish- 
ing the ignition with the cover off. It is best to remove 
,the contents from the filter so far as possible, before ig- 
niting. In many cases, the removal of any of the contents 
is impossible. In such cases, roll up the filter and con- 
tents, and burn both together. If the substance is one 
which may be reduced by the carbon of the filter-paper 
(as lead sulphate, etc.), moisten with a little concentrated 
nitric acid or strong solution of ammonium nitrate before 
igniting. Where the most of the precipitate can be re- 
moved from the filter without loss, it is better to do so, 
and reserve the precipitate in a watch-glass or convex 
cover, until the filter-paper has been consumed. 

Where substances readily reducible are to be weighed, 
which might form a fusible alloy with platinum (lead 
sulphate, silver chloride, etc.), porcelain crucibles should 
be used. 

Note-Books. — Notes should never be kept on loose scraps 
of paper, but in regular note-books, of a size sufficient to 
allow of keeping a clear record of the work, for reference 



10 INTEODTJCTION. 

at any time. It is convenient to get in the habit of setting 
down the weight of the vessel in which a substance is to be 
weighed, in the lower line of the two intended for that 
purpose. In the case given below, the glass for the iron 
wire and the crucible for the precipitate are always 
weighed first, but the weight is entered on the lower line 
of the two, for convenience in subtracting. 

As an illustration of a clear and convenient form of 
keeping a note-book, an example is given. The analysis 
is supposed to be the determination of iron in iron wire : 

Wt. glass -1- Fe wire 6.0765 

" 5.3000 

Fe wire taken 0.7765 

Wt. Crucible + ignited ppt., etc 25.5170 

24.4059 

ppt. + ash 1.1121 

" filter-ash 0.0031 

" ignited ppt 1.1090 

Calculation : 

1.1090 X |H = 0.7763 Fe 
160 

0.7763 X -^ = 99.97 per cent Fe, 
0.7/65 



JVIAKIISTG UP EEAGENTS. 

In making up reagents, pure materials and distilled water 
should be used. In the table below, where salts are men- 
tioned, the crystallized salts (containing water of crystal- 
lization) are meant. Salts obtained from dealers, and 
labelled " chemically pure," are seldom absolutely so, and 
often afford a sediment when their solutions are allowed 
to stand. Tests should always be made for such impurities 
as may interfere with the work. In some cases, the amount 



MAKING UP REAGENTS. 



11 



of impurity may have to be determined, and an allowance 
made for it in the work. 



Reagent. 

Barium Chloride 

Hydro d i s o d i c 
Phosphate 

Ammonium Ox- 
alate 

Argentic Nitrate 



Proportions to be used. 
1 gm. salt 10 c. c. water 

" " " 10 c. c. " 



1 c. c. of solution 
ivill precipitate : 
0.0327 gm. S0 3 



" " " 24 c. c. 
" " " 20 c. c. " 
Sulphuric Acid.. 1 gm. cone. (gr. 1.84) 5 c. c. " 
11 " 1 c. c. " " 5 c. c. " 



0.0112 

0.0145 
0.0104 
0.2522 
0.4291 



Platinic 
ide. 



Chlor- 



[ 1 gm. metal dissolved in aqua regia, 1 0.0390 

-( evaporated to dryness and dissolved } 0.0480 

in 1 c. c. HC1 + 9 c. c. water. 0.0750 



Magnesia niix- 
ture, v i d . 
Fres. Quant 
§ 62.. p. 89. 

3iolybdate sohi- 
t i o n . v i d . 
Fres. Qual. 

79 . 



1 gm. MgS0 4 (salt), 1 gm. NH 4 C1 
(salt), 4 c. c. ammonia, 8 c. c. water. 



1 gm. Mo0 3 dissolved in 4 c. c. am- 



monia, poured into 15 
(gr. 1.2). 



0.0240 



0.0013 



CaO 
CI 
Ba 
Ba 

K 

KC1 



P.O. 



P*0 B 



c. HNCX 

§ 55, p. 72. [ 

Ammonium Carbonate, 1 gm. salt, 1 c. c. ammonia. 

4 c. c. water. 
Sodium Carbonate, 2.7 gm. salt, 5 c. c. water. 

(Saturated solution.) 
Ammonia, gr. 0.96.* 
Hydrochloric Acid, gr. 1.12, 
Nitric Acid, gr. 1.2. 

* The strongest concentrated ammonia has a gr . of 0.880. This, diluted with 
two volumes of water, will have a gravity of 0.96. 



CHAPTEE I. 

BAEIUM CHLOEIDE. 

BaCI 2 .2R 2 0. 
The composition of crystallized baiiiun cliloride is : 

Ba 56.147 per cent. 

CI , 29.099 " " 

H 2 -;'.. :./.... 14.754 " " 

100.000 

Pulverize 8 or 10 gms., and keep the powder in a corked 
tube or bottle. For the determination of the barium, 
dissolve 1 gm. in 100 c. c. warm water, containing a few 
drops of hydrochloric acid. Heat to boiling, and add 2 
c. c. dilute sulphuric acid, prepared by adding 1 part by 
volume of strong acid to 5 parts by volume of water. 
Continue boiling for 1 minute. Then remove the heat, 
and allow the precipitate of barium sulphate to settle 
completely. 

To determine whether or not a sufficient quantity of Sul- 
phuric acid has been added, place 2 or 3 drops of the clear 
supernatant fluid on a watch-glass, and add a drop of 
barium chloride solution. If, upon the addition of the 
barium chloride, the fluid becomes turbid, with a precipi- 
tate of barium sulphate, there is evidently a sufficient 
quantity of sulphuric acid present to precipitate all the 
barium in the solution. Should no turbidity appear after 
adding the barium chloride to the solution on the watch- 
glass, add 1 c. c. more of the dilute sulphuric acid to the 
main solution, boil, and test a few drops of the clear fluid, 
as before. Eepeat the testing and addition of acid until 
the fluid evidently contains an excess. When the pre- 
cipitation is complete, decant the clear fluid on a filter, 
without disturbing the precipitate, pour 100 c. c. boiling 
water on the precipitate, stir well with a glass rod, allow 



CHL0KLNE. 13 

the precipitate to settle, and decant as before. Repeat this 
washing by decantation several times. Then, transfer the 
precipitate to the filter, and wash with hot water until the 
wash- water does not become turbid when either barium 
chloride or silver nitrate is added to it. After filtering 
out the barium sulphate and washing by decantation, and 
before transferring the precipitate to the filter, substitute 
a clean empty beaker for the one containing the filtrate, 
in order that an unnecessary amount of re-filtering may be 
avoided, should the precipitate of barium sulphate run 
through the filter, which sometimes happens when the 
filter-paper is very thin. Dry the precipitate on the filter, 
and when it is dry brush it from the filter into a clock- 
glass or small dish as completely as possible ; burn the 
filter in a weighed crucible, keeping the crucible covered 
until the paper is thoroughly charred. After this, remove 
the cover and continue to heat until the carbon of the 
paper is completely consumed and only white ash left. 
Then transfer the precipitate from the clock-glass to the 
crucible, ignite thoroughly, cool in a desiccator, and weigh. 
The weight will be that of the crucible, filter-ash, and pre- 
cipitate of barium sulphate. Deduct the known weight 
of the crucible and filter-ash, and from the remainder, 
which will be the weight of the barium sulphate, calculate 
the per cent of barium. ; 

The combustion of the filter can be hastened by pressing 
it against the side of the crucible, while burning, with a 
clean glass rod. 

If the barium sulphate be not completely removed from 
the filter before burning it, a little may possibly be re- 
duced to barium sulphide by the carbon of the filter. 
This danger may be avoided by moistening the filter-ash 
with two or three drops of sulphuric acid, drying, and ig- 
niting again, before transferring the precipitate to the 
crucible. 

For the determination of the chlorine, dissolve 0.500 gm. 
of the pulverized barium chloride in a small conical part- 



14 BARIUM CHLOEIDE. 

ing-flask, or matrass, sucli as is used in the assay of gold. 
Fill the flask about half full with warm water — warm to 
about 60° C.j and add 16 c. c. of a solution of silver nitrate ? 
prepared by dissolving 1 part by weight of pure silver 
nitrate in 20 parts of water, add 1 c. c. of nitric acid, cork 
the flask, and shake well. When the precipitate has set- 
tled, add 1 c. c. more of the solution of silver nitrate, and 
notice carefully whether or not it causes another precip- 
itate. If it should do so, shake, and allow the silver chlor- 
ide to settle, add another c. c. of the silver nitrate solu- 
tion, and proceed in the same way until no new precip- 
itate forms, and the solution "brightens," as it is termed ; 
that is, looks perfectly clear. Heat to 60° C. Allow the 
precipitate to settle completely, till the flask with warm 
water, place over the mouth a weighed porcelain crucible 
of a proper size to allow the mouth of the flask to touch 
the bottom of it, and invert it quickly. Hang the flask 
by means of a wire triangle in a ring of an ordinary ring- 
stand, over an evaporating dish sufficiently large to hold 
more than the contents of the flask. Lower the ring until 
the crucible stands on the bottom of the dish, the crucible 
being all the time pressed iirmly against the mouth of the 
flask. Fill the crucible with water and gently raise the 
ring, adding water while doing so, until the mouth of the 
flask is so slightly submerged that a watch-glass, a trifle 
larger than the crucible, can be slipped under it. Do not 
place the watch-glass under the mouth of the flask at first, 
but allow the whole to stand for some hours, protected as 
far as possible from the light. 

The precipitate will usually settle entirely from the 
flask into the crucible ; should any particles adhere to the 
sides of the flask, slight tapping will cause them to de- 
scend. After all the precipitate has settled into the cru- 
cible, slip the watch-glass under the mouth of the flask, 
and, while holding it firmly against it with one hand, 
remove the crucible containing the silver chloride with 
the other ; allow the fluid in the flask to run out slowly 



CHLORINE. 15 

into the dish by moving the watch-glass gently with a 
rocking motion. Now pour the fluid in the crucible care- 
fully into another vessel, or, for greater security, on a filter. 
Wash repeatedly with hot water, containing a little nitric 
acid, decanting on the filter as before, until the washings 
do not become turbid upon the addition of hydrochloric 
acid. In testing, use only a few drops at a time, in a very 
slender test-tube. Remove the last drops of fluid from 
the crucible with a strip of bibulous paper, being careful 
not to take up any silver chloride ; should any particles 
adhere, they can be washed back into the crucible, and the 
fluid removed as before. By a little care and dexterity, all 
but a very small quantity of fluid can, in this way, be re- 
moved. Evaporate ofl what remains in the crucible, and 
then dry it, with its contents, in a drying chamber. 
When all visible moisture is removed, heat over a low 
flame, until the silver chloride begins to fuse well around 
the edge ; cool and weigh. Deduct from this weight the 
known weight of the crucible. The remainder will be the 
weight of the silver chloride. From this, calculate the per 
cent of chlorine. The silver chloride should not be fused 
at a high heat, as it will volatilize some of it. This is the 
best method of determining chlorine gravimetrically, where 
a large quantity of silver chloride is to be handled. 

The silver chloride can be precipitated in a beaker in- 
stead of a flask, and filtered out. Precipitate in the same 
way as directed above ; pour the clear fluid on the filter, 
wash a few times by decantation with hot water acidu- 
lated with nitric acid, transfer the precipitate to the filter, 
and wash with hot water acidulated with nitric acid, until 
the washings do not become turbid upon the addition of 
hydrochloric acid, to be sure that the excess of silver 
nitrate is washed out. Dry the precipitate in the funnel 
in an air-bath. When the precipitate is dry, transfer it to 
a clock-glass, brushing the filter as clean as possible with 
a feather ; place the filter in a weighed porcelain crucible, 
moisten it with a few drops of nitric acid, and burn it 



16 BARIUM CHLORIDE. 

until all carbon is consumed. Let the crucible cool enough 
to be handled, add a few drops of nitric acid, and warm, 
to dissolve the metallic silver which is due to the re- 
duction of the silver chloride by the carbon of the filter. 
Then add a few drops of hydrochloric acid and evaporate 
to dryness. Transfer the precipitate from the clock-glass 
to the crucible, fuse as directed above, cool and weigh. 
The weight will be that of the crucible, filter-ash and silver 
chloride. Deduct the known weight of the crucible and 
ash of filter ; the remainder will be the weight of the silver 
chloride. From this, calculate the per cent of chlorine. 

Whichever method be employed, evaporate the filtrates 
and washings to small bulk, after adding a little silver 
nitrate and nitric acid. Should a precipitate of silver 
chloride be formed, treat it as directed above, and add the 
per cent to the first. 

For the determination of water, introduce 1 gm. into a 
weighed crucible, and heat very gently to low redness ; 
cool and weigh. Repeat the heating and weighing until 
the substance ceases to diminish in weight. Care should 
be taken not to heat too highly, as by doing so some 
chlorine may be expelled. 

The loss of weight is equivalent to the water ; from this, 
calculate the £>er cent of water. 



CHAPTER n. 

MAGNESIUM SULPHATE. 

MgS0 A .1H 2 0. 
The theoretical composition of magnesium sulphate is : 

MgO 16.26 per cent, 

S0 3 > 3252 " " 

H 2 51.22 " " 

100.00 

As the salt is slightly efflorescent, select 8 or 10 gms. of 
crystals that have not ]ost water by exposure, pulverize 
them quickly, and keep the powder in a corked tube or 
bottle. 

For the determination of magnesia, dissolve about 1 gm. 
in 25 c. c. of cold water in a small beaker, add enough 
hydrochloric acid to make the solution distinctly acid to 
test-paper, and then enough ammonia to make it de- 
cidedly alkaline. Should a precipitate of magnesium 
hydrate occur, make the solution acid again with hydro- 
chloric acid, and then alkaline again with ammonia, as be- 
fore. Repeat this treatment if necessary until ammonia 
no longer produces a precipitate. Allow the fluid to 
cool, and add 16 c. c. of a solution of hydro-disodium 
phosphate, prepared by dissolving 1 part by weight of the 
salt in 10 parts of water. Agitate the contents of the 
beaker well with a glass rod, being careful not to rub the 
sides of the vessel with the rod, as it will cause crystals of 
ammonia-magnesium phosphate to adhere to the glass so 
tenaciously as to be difficult to remove. Allow the solution 
to stand cold 12 hours, and, when the precipitate has en- 
tirely settled, place 3 or 4 drops of the clear fluid on a watch- 
glass, or in a very small test-tube, and add 2 or 3 drops of 
" magnesia mixture." If a precipitate forms, it shows 
that enough hydro-disodium phosphate has been used ; if 
no precipitate forms, add 5 c. c. of the precipitant to the 
main solution, and proceed as before. Filter on a very 



18 MAGNESIUM SULPHATE. 

small filter, and wash with dilute ammonia, prepared by 
mixing 1 part of strong ammonia with 2 parts of water, 
until no turbidity is produced by silver nitrate in 1 c. c. 
of the washings acidulated with nitric acid, or by barium 
chloride in the same quantity acidulated with hydro- 
chloric acid. Dry the precipitate on the filter, and, when 
it is dry, brush it from the filter into a large watch-glass, 
and burn the filter in a weighed crucible. When the car- 
bon of the filter is entirely consumed, transfer the pre- 
cipitate to the crucible, and ignite again, increasing the 
heat to bright redness, keeping the crucible covered. Then 
remove the cover, and heat strongly, until the contents of 
the crucible are white, or nearly so. Should the contents 
of the crucible appear dark in color, moisten them with 
a few drops of nitric acid ; evaporate off the excess of acid 
carefully, and ignite again, until the precipitate is of a 
light gray color. Cool the crucible and contents in a 
desiccator, and weigh. Deduct the known weights of 
the crucible and filter-ash. The remainder will be the 
weight of the magnesium pyro-phosphate (Mg 2 P 2 7 ). 
From this weight calculate the per cent of magnesia. 

For the determination of the S0 3 dissolve 1 gm. in 100 
c. c. warm water, acidulate slightly with hydrochloric 
acid, boil, add 12 c. c. of a solution of barium chloride — 
prepared by dissolving 1 part by weight of crystallized 
barium chloride in 10 parts of water — and continue the 
boiling for 2 or 3 minutes. Allow the precipitate to settle, 
and test a few drops of the clear fluid with sulphuric acid. 
If no precipitate is produced by the sulphuric acid, there 
cannot be an excess of barium chloride in the solution. In 
such a case, add another c. c. of barium chloride solution, 
stir, and allow the precipitate to settle, and test again. 
Proceed in the same way, until the appearance of a pre- 
cipitate upon testing shows that there is a sufficient quan- 
tity of barium chloride present. Finally, allow the pre- 
cipitate to settle, decant the clear fluid on a filter, pour on 
the precipitate 100 c. c. of boiling water containing 2 or 3 



WATER OF CRYSTALLIZATION. 19 

c. c. of hydrochloric acid, stir, allow the precipitate to 
settle, and again decant on the filter. Repeat this treat- 
ment, and then transfer the precipitate to the filter with 
hot water, and wash with the same until a few drops of 
the wash-water show no turbidity when treated with 
silver nitrate, and leave no more residue, when evaporated 
on platinum and ignited, than will be left by a similar 
quantity of distilled water, treated in the same way. Dry 
the precipitate, brush it on a clock-glass, burn the filter 
moistened with a few drops of sulphuric acid in a weighed 
crucible, add the precipitate, ignite strongly, cool, and 
weigh. Deduct the known weights of the crucible and 
filter-ash. The remainder will be the weight of the barium 
sulphate. From this calculate the per cent of S0 3 . 

As the precipitate of barium sulphate has a tendency to 
carry down with it barium chloride, which it is difficult to 
remove by washing, after igniting the precipitate, brush it 
from the crucible into a beaker, moisten with a few drops 
of hydrochloric acid, add water, and boil. Then transfer 
all to a filter, wash well, dry, ignite, and weigh. Where 
barium sulphate has been precipitated in a fluid contain- 
ing salts of iron, it is nearly impossible to purify it in this 
manner. In such a case, fuse the ignited precipitate with 
a little sodium carbonate, digest the mass with boiling 
water until it is disintegrated, transfer it to a filter, and 
wash well. By this means, the barium will remain on the 
filter as carbonate, with the impurity, while the sul- 
phuric acid will pass into the filtrate, from which it can 
be precipitated free from impurity. 

For the determination of the water, introduce about 1 
gm. of the salt into a weighed crucible, heat to redness, 
cool, and weigh. Again heat, cool, and weigh. Repeat 
until the crucible and contents no longer lose weight by 
being heated. The difference between the weights of the 
crucible and contents, before and after heating, is due to 
the loss of water. From this, calculate the per cent of 
water. 



CHAPTER III. 

CaC0 3 . 



The theoretical composition of calcite is : • 

CaO 56.00 per cent. 

C0 2 44.00 " " 



100.00 

For the determination of the lime, dissolve 1 gm. in 3 
c. c. of strong hydrochloric acid, and 25 c. c. of boi^g 
water. It should dissolve completely ; should it not, filter,** 
ont any residue, and.wash with about 50 c. c. of hot water. 
Then wash the residue from the filter into a very small 
beaker with as little water as possible, and add 2 c. c. of 
hydrochloric acid, and boil. Should it dissolve, add the 
solution to the first one ; should it not dissolve, pass the 
fluid through the same filter, wash, and add the filtrate to 
the firs + solution. The combined solutions should not 
amount to more than 200 c. c. Dry the insoluble residue, 
burn it in a weighed crucible, and deduct its weight from 
the original weight of substance. The difference expresses 
the actual weight of calcite taken for analysis. To the 
combined solutions add enough ammonia to make the 
fluid decidedly alkaline to test-paper, heat to boiling, and 
add 50 c. c. of ammonium oxalate solution, prepared by 
dissolving 1 part by weight of the salt in 24 parts of water. 
Boil hard for two or three minutes. Then remove the 
heat, allow the fluid to cool and the* precipitate to settle. 
To be sure that enough ammonium oxalate has been used, 
put 3 or 4 drops of the clear fluid on a watch-glass 
or in a small test-tube, add 1 drop of ammonia and two or 
three drops of solution of calcium chloride. The forma- 
tion of a precipitate proves that enough ammonium ox- 
alate was used in the first instance. If no precipitate 



LIME 21 

forms, add 10 c. c. more ammonium oxalate to the main 
solution, and test again in the same way. Proceed in this 
manner until assured that enough of the precipitant has 
been added. When the precipitate has thoroughly set- 
tled, decant the clear fluid on a filter, after pouring off as 
much of the fluid as possible. Without disturbing the 
precipitate, remove the beaker containing the filtrate, and 
place another under the funnel. Then transfer the pre- 
cipitate to the filter with hot water, and wash it down into 
the point. More washing than will effect that object is 
unnecessary, as the impurities that may possibly be pres- 
ent, that is, ammonium chloride and oxalate will be 
expelled by the after-treatment of the calcium oxalate 
with sulphuric acid. The object aimed at in remov- 
ing the beaker containing the filtrate is to avoid having to 
re-filter a large amount of fluid, should the precipitate of 
calcium oxalate run through the filter, as it sometimes 
does, particularly when the filter-paper is very thin. 
Remove any calcium oxalate adhering to the walls of 
the beaker with a feather or rubber. If any adhere so 
tenaciously as to render it impossible to remove it with a 
rubber, wash it off with a little dilute hydrochloric acid 
into a small beaker ; add ammonia to alkaline reac- 
tion, a few drops of ammonium* oxalate, and boil two or 
three minutes. When the precipitate has settled, filter 
through the same filter. The water required to transfer 
the precipitate to the filter will wash it sufficiently. Dry 
the filter and contents at a temperature not exceeding 100° 
C, to avoid making the filter brittle. When the precip- 
itate is dry, brush it into a clock-glass, cleaning the filter 
as thoroughly as possible. Burn the filter in a weighed 
crucible until only white ash is left. Remove the heat, 
and when the crucible is cool, transfer the precipitate from 
the glass to the crucible, add enough strong pure sulphuric 
acid to moisten the precipitate, place the lid on the crucible 
and expel the excess of sulphuric acid by heating over a 
Bunsen burner, allowing the flame to touch only the lip 



22 



CALCIUM CAKBONATE. 



or edge of the crucible cover. After expelling all free sul- 
phuric acid, ignite strongly for a few minutes, cool in a 
desiccator, and weigh. This weight, after deducting the 
known weights of crucible and filter-ash, will be that of 
calcium sulphate. From this calculate the per cent of 
lime. 

The filter should be cleaned as thoroughly as possible, 
as ignition will convert any adhering calcium oxalate into 
calcium hydrate or carbonate which will effervesce vio- 
lently upon the addition of sulphuric acid, thereby causing 
loss of substance, by projecting it from the crucible. The 
reaction between calcium oxalate and sulphuric acid takes 
place without any violent action. 

The carbonic acid is determined by loss of weight of the 
substance after expelling the gas, or by weighing the gas 
after absorbing it in potassium hydrate, or soda-lime. 

There are a great many kinds of apparatus devised by 
chemists for determining carbonic acid by loss. One 
which every one can prepare for himself, is constructed of 
3 small flasks, A, B, and (7, two of which, A and B, hold 
about 100 c. c. each, and the third, or C, about 25 c. c. 




Each flask is provided with a doubly -perforated cork, or 
rubber stopper. Through the first hole of the stopper of 
flask A passes a piece of small glass tubing, about one 



CARBON DIOXIDE. 23 

and a half inches long. Through the other hole, passes, 
nearly to the bottom of the flask, one limb of a glass tube 
bent twice at right angles, the other limb of which passes 
through the first hole of the stopper of the other 100 c. c. 
flask, B, nearly to the bottom. Through the other hole of 
the stopper of flask B, sufficiently far to clear the stopper, 
passes the short limb of a tube, bent twice at right angles, 
while the longer limb passes through the first hole of the 
stopper of the 25 c. c. flask, (7, nearly to the bottom. 
Through the other hole, passes a short tube, about one and 
a half inches long. Into flask A, introduce 30 c. c. of dilute 
nitric acid ; into flask B, a carefully- weighed quantity of 
the calcium carbonate (about 1 gm.), and into flask O, 10 
c. c. of concentrated sulphuric acid. Put the apparatus 
together, and weigh. Then draw a little acid over from A 
into B, by sucking at the exit tube of (7, and close the 
open tube of A by placing over it a short piece of rubber 
tubing, the other end of which is closed by a piece of glass 
rod. When the violent effervescence is over, open the 
closed tube of A, and repeat the operation, until enough 
acid is drawn from A into B to decompose the calcium 
carbonate. Then close the open tube of A, and raise the 
contents of the flask B, to incipient boiling. Then re- 
move the heat ; at the same time, remove the stopper from 
the open tube of A, attach in its place a small calcium- 
chloride tube, containing equal parts of calcium chloride 
and soda lime, and draw a gentle current of air through 
the apparatus by means of an aspirator. The air should 
not pass more rapidly than at the rate of 2 bubbles in a 
second, or the aspiration be continued longer than is nec- 
essary to clear the apparatus of carbonic acid. The pas- 
sage of half a litre of air will effect this. The amount can 
be determined by the volume of water that escapes from 
the aspirator. The carbonic acid can be sucked out by the 
mouth. If this plan be adopted, the air should be drawn 
through until it no longer tastes of carbonic acid. After 
a sufficient volume of air has been drawn through the 



24 Cj^CITJM carbonate. 

apparatus to extract the carbonic acid, allow the apparatus 
to cool, remove the aspirator, if one has been used, and 
the calcium-chloride tube from the open tube of flask A y 
and weigh. The difference between this and the first 
weight of the apparatus is equivalent to the weight of 
carbonic acid. In many cases, the determination of car- 
bonic acid by loss is inadmissible. It such cases, it is 
absorbed in some substance with which it will combine, as 
potassium hydrate or soda-lime. For this purpose, an 
apparatus such as that described by Fresenius in his 
work on Quantitative Analysis (§ 139 e p. 293), under the 
head of carbonic acid, can be used. In making the de- 
termination, do not use more than 0.500 gm. of calcium 
carbonate, as a large quantity necessitates the use of 
large absorption tubes. If soda-lime be used, it is well 
not to use the tube after more than one half of the con- 
tents have been heated by the carbonic acid. 

For the analysis, weigh the absorption tubes, introduce 
the weighed substance into the decomposing flask, put 
the apparatus together, close the stop-cock of the funnel- 
tube, and attach the aspirator. After the aspirator has 
drawn long enough to produce a partial vacuum in the 
apparatus, introduce about 30 c. c. of dilute nitric acid, 
through the funnel-tube, into the decomposing-flask. As 
soon as all the acid is in, close the funnel-tube. After the 
first violent effervescence has ceased, apply gentle heat to 
the flask, and gradually increase it, until the fluid in the 
flask begins to boil. Then remove the heat, attach the 
guard tube, containing soda lime and calcium chloride, 
open the stop-cock or clamp, and draw air through the 
apparatus, very slowly, until the absorption tubes are 
cool, or until about 2 litres of air have passed through. 
When the tubes are cool, weigh them. The difference be- 
tween this weight and the first weight of the tubes is 
equivalent to the carbonic acid. The carbonic acid can 
also be determined by introducing a weighed quantity 
into a tube of hard glass, by means of a small platinum 



CARBON DIOXIDE. 



25 



boat, and igniting strongly, at the same time, drawing 
through the tube a current of dried air. Attach to the 
tube a weighed tube, filled with neutral calcium chloride, 
over which carbon dioxide has been passed for some time. 
This will absorb the water, and allow the carbonic acid to 
pass. After the carbonic acid is expelled from the sub- 
stance, weigh both the boat and contents, and also the 
calcium-chloride tube. The loss of weight of the boat 
will be carbonic acid plus water, while the increase of 
weight of the calcium-chloride tube will be water. The 
difference between the weight of carbonic acid and water, 
determined by loss, and the weight of water will be that 
of carbonic acid. Not more than 0.500 gm. of substance 
should be used. 



Note. — The apparatus used in the estimation of the carbonic acid is repre- 
sented below. 




a contains soda-lime ; it can be attached to b with a cork, b is provided with 
a glass tap. The flask c has a capacity of 200 c. c. d contains sulphuric acid, e 
contains pumice saturated with sulphuric acid, /contains pumice which has 
been saturated with solution of sulphate of copper, and then heated strongly till 
all the water has been expelled, g contains soda-lime and h sulphuric acid on 
pumice. The pumice used in this apparatus should be previously heated with 
strong sulphuric acid, washed and dried, as it is liable to contain chlorides and 
fluorides. The loose sulphuric acid in the U tubes should not rise above the bend 
when at rest. 

g and h are the only pair in the train which are weighed. They should be 
provided with rubber tubes, stopped with glass rod to prevent absorption of 
carbonic acid or moisture from the air. 



CHAPTER IV. 

POTASSIUM ALUM. 

AlK(SO±) 2 .12IT 2 0. 
The theoretical composition of potassium alum is : 

A1 2 3 10.86 per ceni. 

K 2 9.90 " •< 

S0 3 33.72 " •' 

H 2 45.52 " " 

100.00 

Pulverize 5 or 6 gms. coarsely and quickly, and keep 
the powder in a small corked bottle, or specimen tube. 
For the determination of alumina, first weigh the tube, 
and contents ; then shake out a little into a beaker, and 
again weigh the tube, and remaining substance. The 
diminution in weight, of course, shows the amount taken. 
Proceed in this way until about 1 gm. has been trans- 
ferred to the beaker. Pour upon it 100 c. c. of hot water 
and stir ; when all is dissolved, add 2 or 3 c. c. of strong 
hydrochloric acid, and enough ammonia to turn red test- 
paper blue, and emit a slight odor of ammonia. Be 
cautious not to add a large excess, or time will be wasted 
in boiling it out, which will be necessary for the reason 
that aluminum hydrate is somewhat soluble in excess ol 
ammonia. Boil until the vapors no longer smell of 
ammonia, and do not turn turmeric paper brown. Allow 
the precipitate to settle, and decant the clear fluid on a 
filter. Then pour 40 or 50 c. c. of boiling water on the 
precipitate, stir, allow it to settle, and decant the clear 
fluid on the filter as before. Repeat this treatment several 
times, and finally transfer the precipitate to the filter, 
with boiling water, and wash with the same, until a few 
drops of the wash-water, acidulated with nitric acid, do 
not show a precipitate of silver chloride when treated with 



i0T POTASSIUM. 27 

a drop of silver nitrate, or a precipitate of barium sul- 
phate when treated with hydrochloric acid and barium 
chloride. It is unnecessary to begin washing on the filter 
until about 1 00 c. c. have passed through the filter. Test 
the filtrate and washings with litmus paper. If they are 
not alkaline, add ammonia until the fluid is faintly alka- 
line, and heat. Should a precipitate appear, filter it out, 
wash, dry it, and reserve it to be burned with the other. 
When the main precipitate is perfectly dry, ignite it, with 
the smaller one, should there be any, rolled up in the 
filter, in a weighed crucible furnished with a lid, apply- 
ing the heat gently at first, and then intensely, in order to 
expel any adhering sulphuric acid. During the latter 
part of the ignition remove the cover from the crucible, in 
order thoroughly to consume the filter. When the filter 
is completely burned, remove the heat, cool and weigh. 
This weight, after deducting the weight of the crucible 
and filter-ash, will be the weight of the alumina. 

For the determination of S0 3 concentrate the filtrate 
from the alumina to 200 c. c. by evaporation, add hydro- 
chloric acid until the fluid is slightly acid, and then add 
12 c. c. of barium chloride solution, prepared by dissolv- 
ing 1 part by weight of crystallized barium chloride in 10 
parts of water. Boil for a few minutes and allow the pre- 
cipitate of barium sulphate to settle, and proceed as di- 
rected in the analysis of magnesium sulphate. Observe 
the precautions there given, as to washing and purification 
of the precipitate. 

To determine the potassium, add ammonia to the filtrate 
from the barium sulphate until it is slightly alkaline, 
heat to boiling, and add ammonium carbonate as long as 
it produces a precipitate of barium carbonate. When all 
the barium is precipitated, decant the clear fluid on a 
filter, wash by decantation 3 or 4 times, using about 50 
c. c. of hot water each time, transfer the precipitate to the 
filter, and wash it well with hot water, or until 2 or 3 
drops of the wash- water, acidified with nitric acid, show 



28 POTASSIUM ALUM. 

no cloudiness when treated with silver nitrate. Pour 3 or 
4 funnelfuls through the filter before beginning to test. 
When all the potassium chloride is washed out, evaporate 
the filtrate and washings to dryness in a platinum dish, 
and ignite to faint redness, until all the ammonium 
chloride is expelled. This may be ascertained by holding 
over the vessel a clean cold clock-glass. The non-appear- 
ance of a white coating on the glass indicates the absence 
of ammonium chloride. Dissolve the residue in about 25 
c. c. of warm water, filter the solution into a small porce- 
lain dish, and wash with hot water, testing the wash-water 
with silver nitrate, as directed above, to be sure that all 
potassium chloride is washed out. When the filter and 
contents are sufficiently washed, add to the fluid 2 drops 
of concentrated hydrochloric acid and 8 c. c. of platinum 
tetrachloride solution, prepared by dissolving 1 part by 
weight of platinum tetrachloride in 10 parts of water, and 
evaporate to a pasty consistency, on a water-bath. Then 
pour into the dish about 50 c. c. of alcohol, of about 85 
per cent, without removing the dish from the bath, and 
heat for two or three minutes. Then wash the contents of 
the dish into a small flask, marked A, with alcohol of 85 
per cent, and cork it immediately, to avoid the possibility 
of absorption of ammonia from the air of the laboratory, of 
which there is frequently great danger. After the potas- 
sium platino-chloride has entirely settled, and the fluid 
shows by its color that a sufficient amount of platinum 
tetrachloride has been added, pour off the clear fluid into 
another flask, marked B, as completely as possible with- 
out transferring any of 'the precipitate, cork it, and allow 
it to stand long enough for any particles of potassium 
platino-chloride, which may have passed over with the 
fluid from flask A, to subside. Then pour into the first 
flask, A, 20 or 30 c. c. of 85 per cent alcohol, cork it, and 
after agitating it gently set it aside, until the contents of 
the flask B are disposed of. Pour the contents of B into 
a dish, add about 10 c. c. of water, and proceed to evapo- 



POTASSIUM. 29 

rate off the alcohol on a water-bath. Should there be any 
particles of the precipitate in the fluid, first pour off as 
much as possible into the dish, without disturbing the 
precipitate, and evaporate it as above, and pour the rest, 
with the precipitate, on a filter. Add this filtrate to the 
fluid already evaporating. Keep the funnel covered with 
a glass while filtering. After all the fluid has thus been 
transferred to the dish for evaporation, pour upon the 
same filter the contents of flask A, washing the precipitate 
into the filter with 85 per cent alcohol. Dry the filter 
and contents in an air-bath at 100° C. Ignite the dry pre- 
cipitate, rolled up in the filter, in a weighed crucible, 
applying the heat very gently at first, and keeping the 
crucible covered until the filter-paper is charred. Then 
remove the cover from the crucible, and ignite at a higher 
degree of heat, until the filter is entirely consumed. 
Allow the crucible to cool, add a little oxalic acid, heat 
gently at first, until the water of crystallization of the 
oxalic acid is expelled, and then more intensely until the 
acid is decomposed, and all the carbon consumed. Cool 
the crucible, and wash by decantation with hot water as 
long as the wash- water becomes turbid from formation of 
silver chloride, when treated with silver nitrate. By this 
means, the double chloride is decomposed, and all the 
potassium and chlorine washed out, leaving only spongy 
platinum. Heat alone fails to decompose the compound 
completely. 

After the platinum is sufficiently washed, dry the cru- 
cible and contents, and ignite until every thing is con- 
sumed but spongy platinum. Cool, and weigh. Deduct 
from this weight, that of the crucible and filter-ash. The 
remainder will be the weight of platinum. From this, 
calculate the per cent of potassium or of potassium oxide. 

After all the alcohol has been expelled from the original 
filtrate by evaporation, as directed above, add 1 c. c. of 
platinum tetrachloride solution, and a very small quantity 
of pure sodium chloride ; continue the evaporation to 



30 POTASSIUM ALUM. 

pasty consistency, treat with alcohol, and proceed as 
directed for the treatment of the main precipitate. Should 
any more potassium platino-chloride be obtained, treat it 
as above, and add the per cent to that of the main pre- 
cipitate. The sodium chloride tends to prevent the de- 
composition of the platinum chloride, while evaporating 
the alcoholic solution. 

Instead of igniting the dry precipitate ,of potassium 
platino-chloride, it may be weighed as such. In this case, 
filter through an exhausted filter ; that is, one which has 
been previously washed with hydrochloric acid, and then 
with water until all the acid is removed from the paper. 
Then dry the filter between watch-glasses, held together 
by a clip. After weighing the glasses, clip, and paper to- 
gether, previously dried at 100° C, transfer the filter to a 
funnel, and filter the solution through it. Dry the filter 
and precipitate first in the funnel at 100° C. Then place 
them between the glasses, secure the glasses by means of 
the clip, dry again at 100° C, cool, and weigh. The in- 
crease in weight will be that of the precipitate of potas- 
sium platino-chloride. From this, calculate the per cent 
of potassium. This method is tedious and objectionable 
where a small quantity of potassium platino-chloride is 
to be dealt with. If great care is exercised in preparing 
and drying the filter, it may be adopted where a large 
amount of potassium is to be determined. 

For the determination of water, weigh about 1 gm. 
shaken from the tube, as directed above, into a weighed 
crucible, heat to 250° C, cool, and weigh. Repeat the 
heating and weighing until the substance ceases to lose 
weight. The loss of weight is equivalent to the weight of 
water expelled. From this, calculate the per cent of 
water. 



CHAPTER V. 

CALCIUM FLUOEIDE. 

CaM 2 . 

The theoretical composition is : 

Ca 51.28 per cent. 

Fl 48.72 " 



100.00 

Introduce into a weighed platinum crucible 1 gm. of 
the finely -powdered mineral, mix it, by means of a coarse 
platinum wire, with pure concentrated sulphuric acid, to 
the consistence of paste ; add enough more acid to make 
the mixture semi-fluid, place the crucible with the cover 
on, in an inclined position on a support, and heat with a 
Bunsen burner, allowing the flame to strike the edge of 
the crucible and lid. Continue heating until all the sul- 
phuric acid is expelled, and the calcium converted into 
sulphate, cool, weigh, and calculate the weight of calcium. 
The difference between the weight of calcium and the 
weight of mineral taken is equivalent to the weight of 
fluorine expelled. From these data, calculate the per cent 
of calcium and fluorine. 

There are various methods for determining fluorine, 
varying in complexity with the character of the sub- 
stances treated. It was suggested by Berzelius (Rose, p. 
883) to distill the fluoride of silicon from substances that 
could be decomposed by sulphuric acid, by heating with 
this acid, adding powdered silica if necessary, in a retort 
of lead or platinum, delivering into a vessel of water. The 
acid used must be pure and concentrated, the silica pure 
and in the form of very fine powder, and the metallic tube 
connected with the retort must dip into mercury just far 
enough to prevent the point from coming in contact with 



32 CALCIUM FLUOEIDE. 

the water, or the separated silica will clog it. The fluoride 
of silicon, when it comes in contact with the water, is 
decomposed into silica, which separates, and hydro-fluo- 
silicic acid, which goes into solution. Filter out the silica, 
wash it well, dry, and weigh it. To the acid fluid 
containing hydro-fluosilicic acid, Rose (lb. p. 883) adds 
potassium chloride and alcohol. The potassium silico- 
fluoride is collected on a weighed filter, washed with 
dilute alcohol, consisting of equal parts of alcohol and 
water, dried at 100° C, and weighed. The fluorine calcu- 
lated from the silica, and from the precipitate of potas- 
sium silico-fluoride, will together give the per cent in the 
substance. 

SSiF, + 3& 2 = lI 2 SiO B + 2B 2 SiF 6 . 

To determine the fluorine in substances insoluble in 
water, and not decomposable by acid, Berzelius (Vid. 
Fres. Quant., § 166a) fused the substance with 4 parts 
of sodium carbonate at a strong red heat, digested the 
mass in water, boiled, filtered, and washed, first with 
boiling water, then with a solution of ammonium car- 
bonate. The filtrate will contain all the fluorine as 
sodium fluoride, together with carbonate, silicate, and 
aluminate of sodium. The filtrate is to be mixed with 
ammonium carbonate, and the mixture heated, the am- 
monium carbonate which evaporates being replaced. 
The aluminium hydrate and silicic acid is then filtered off 
and washed with ammonium carbonate. The filtrate is 
then heated until the ammonium carbonate is completely 
expelled, and the fluorine determined. Rose suggests a 
modification of Berzelius' s treatment after reaching this 
point, which is as follows : Add a solution of calcium 
chloride as long as a precipitate continues to form. When 
the precipitate, which consists of calcium fluoride, and 
calcium carbonate, has subsided, it is washed, first by 
decantations, afterward on the filter, and dried. When 
dry, it is ignited in a platinum crucible. Water is then 



FLUORINE. 33 

poured over it, in a platinum or porcelain dish, acetic 
acid added in slight excess, the mixture evaporated to 
dryness on a water-bath, and heated on the latter until 
all odor of acetic acid disappears. The residue, which 
consists of calcium fluoride and calcium acetate, is heated 
with water, the calcium fluoride filtered off, washed, dried, 
ignited, and weighed. If the precipitate of calcium 
fluoride and calcium carbonate were treated with acetic 
acid, without previous heating, the washing of the fluor- 
ide would be very difficult. From the weight of the 
calcium fluoride, calculate the per cent of fluorine. 
See H. Eose, Anal. Ohem., chapter on Fluorine, p. 757. 



CHAPTER VI. 

POTASSIUM IODIDE. 

KL 

The theoretical composition is : 

K 23.545 per cent. 

1 76.455 " " 



100.000 

To determine the potassium, dissolve 1 gm. of the salt 
in about 10 c. c. of water, in a small porcelain dish, add 
2 or 3 c. c. strong nitric acid, and evaporate to dryness on 
the water-bath, to expel the iodine. It may be necessary 
to repeat this operation in order to drive out the last traces 
of the iodine. Take up with about 20 c. c. of water, add 
1 c. c. strong hydrochloric acid, and proceed as directed 
in the analysis of potassium alum. 

To determine the iodine, weigh carefully 0.250 gm. of 
the salt, transfer it to a parting flask, add warm water, an 
excess of silver nitrate and nitric acid, and proceed as 
directed in the analysis of barium chloride, for the deter- 
mination of chlorine, care being taken to add excess of 
silver nitrate before adding the nitric acid. 

The iodine can also be determined with great accuracy 
by precipitating it, as palladium iodide, in a solution of 
the salt, slightly acidified with hydrochloric acid, warm- 
ing gently and allowing the whole to stand for about 24 
hours, to give the precipitate ample time to form and 
settle. It is better finally to ignite the precipitate, and 
from the metallic palladium calculate the iodine. 

See Fres., § 145— 1— b, p. 311, and H. Rose, chapter on 
Iodine, p. 824. 



CHAPTER VII. 

POTASSIUM BROMIDE. 

KBr. 
The theoretical composition of the salt is : 

K .. 32. 835 per cent. 

Br 67.165 " " 



100.000 

For the determination of the potassium, proceed exactly 
as in the previous analysis of potassium iodide, or boil 
with dilute chlorine water until the bromine is expelled, 
and then proceed. 

The bromine is determined as silver bromide, in the 
same manner as chlorine is determined as silver chloride, 
in the analysis of barium chloride. 

See H. Hose, Anal. Chem., chapter on Bromine, p. 815- 









CHAPTER YIII. 

HYDRO-DISODIUM PHOSPHATE. 

The theoretical composition of hydro-disodium phos- 
phate is : 

Na 2 17.32 per cent. 

P 2 5 19.83 " " 

H a O 62.85 " " 

100.00 

Select 4 or 5 gins, of the crystals which have lost no 
water by efflorescence, break them up quickly into a 
coarse powder, and keep the powder in a small, well- 
corked bottle or large specimen tube, and weigh the 
portions required for analysis as directed in the case of 
potassium alum. 

Perhaps a better plan is to dissolve about 5 gms. in 100 
c. c. of water, transfer the solution to a 250 c. c. flask, 
dilute to the holding mark, and mix the fluid well by 
pouring several times from the flask into a beaker and 
back. Then draw from the flask with a pipette the quan- 
tity required for analysis, and cork the flask to prevent 
evaporation of the fluid. 

For the determination of sodium, dissolve about 1 gm. 
of the salt in about 50 c. c. of water, or take an equivalent 
amount from the solution of a large quantity. Then dis- 
solve about 0.600 gm. piano-forte wire in 30 c. c. dilute 
hydrochloric acid, add 3 c. c. of strong nitric acid, and 
boil. Then concentrate the solution until nearly all free 
acid is expelled, dilute with 10 c. c. of water, and add the 
solution'to that of the sodium phosphate. To the com- 
bined solutions add ammonia in excess, and heat to 
boiling. Then remove the heat, and allow the precipitate 
to settle. When the precipitate has settled thoroughly, 



PHOSPHORIC ANHYDRIDE. 37 

and the supernatant fluid become colorless, filter off the 
clear fluid, and wash the precipitate three or four times, 
using 50 or 60 c. c. of hot water each time. Then transfer 
the precipitate to the filter, and wash again with hot 
water, until the washings show only a slight opalescence 
upon addition of silver nitrate and nitric acid. In testing 
the -washings, use only 2 or 3 drops each time. The 
precipitate will contain all the phosphoric acid, combined 
with the ferric oxide, and may be rejected. Evaporate 
the filtrate and washings to dryness on a water-bath. Just 
before the point of dryness is reached, add dilute hydro- 
chloric acid, little by little, until the fluid is slightly acid 
to test-paper. By delaying the addition of the acid until 
nearly all the ammonia is expelled by the evaporation, 
there will be less ammonium chloride to burn out, and less 
danger of loss of sodium chloride by ignition. Continue 
the evaporation, and, when the mass is perfectly dry, ignite 
gently until vapor of ammonium chloride ceases to be 
evolved. Cool, dissolve in a little boiling water, and filter 
into a weighed platinum dish ; washing the filter until a 
few drops of the wash-water do not give a precipitate of 
silver chloride, when treated with silver nitrate. Then 
evaporate the filtrate to dryness, ignite gently, and weigh 
the sodium chloride. From this weight, calculate the per 
cent of soda. The ignited sodium chloride should be 
white and perfectly soluble in water. - If it is not, filter 
the solution, wash the insoluble residue, evaporate the 
filtrate and washings to dryness, ignite, and weigh again. 
For the determination of phosphoric acid, take 1 gm. of 
the salt, weighed as directed in the analysis of potassium 
alum, or a portion of a solution of larger quantity equiva- 
lent to 1 gm. If 1 gm. of the solid salt is taken, dissolve 
it in 50 c. c. of cold water, acidify the solution with hy- 
drochloric acid, and then make it slightly alkaline with 
ammonia. When the solution is cool, add 12 c. c. of 
' e magnesia mixture, ' ' and set it aside for some hours. The 
"magnesia mixture" is prepared by dissolving 1 part by 



38 HYDEO-DISODITJM PHOSPHATE. 

weight of crystallized magnesium sulphate and 1 part by 
weight of ammonium chloride in 8 parts of water and 4 
parts of ammonia. After the precipitate of ammonio- 
magnesium-phosphate has entirely settled, filter, wash 
with dilute ammonia until the washings give no reaction 
for sulphuric acid, and place the funnel containing the 
precipitate in an air-hath to dry. Eeserve the filtrate for 
some hours. Should another precipitate appear, filter it 
out on the smallest-sized filter, wash it with 20 or 30 c. c. 
of dilute ammonia, dissolve it through the filter with a 
little dilute hydrochloric acid into a small beaker, and 
make the solution alkaline with ammonia. If the ammo- 
nia produces a precipitate, filter it out, wash it with dilute 
ammonia, dry, and ignite with the main precipitate of 
ammonio-magnesium-phosphate. Ignition converts this 
into magnesium pyrophosphate. From this, after weigh- 
ing and deducting the weight of the crucible and filter-ash, 
calculate the per cent of P s O G . It sometimes happens 
that, in precipitation of phosphoric acid by means of 
magnesia mixture, some magnesium hydrate is precipi- 
tated with the phosphate. When there is reason to sus- 
pect that such has been the case, from the flocculenfc 
appearance of the precipitate, dissolve the ignited precipi- 
tate of pyrophosphate in a little hydrochloric acid, dilute 
slightly, add a few drops of nitric acid, and boil gently 
for about an hour, renewing the fluid from time to time. 
.By this means, the pyrophosphoric acid will be converted 
into the tribasic acid again. Then make the fluid alkaline 
with ammonia. The ammonio-magnesium-phosphate will 
be precipitated free from magnesium hydrate, and is to be 
treated as directed above. It is necessary to convert the 
pyrophosphoric or tetrabasic into the tribasic acid before 
adding the ammonia, as the pyrophosphate is soluble to 
an appreciable extent in ammonia water. 

For the determination of the water, weigh 1 gm. of the 
phosphate in a boat made of platinum foil. Introduce the 
boat into a tube of hard glass about 8 or 10 inches long, 



WATER OF CRYSTALLIZATION. 39 

such as is used for combustion in organic analysis. One 
end of this tube is clojed by a cork, through which passes 
a short piece of smalleT glass tubing, while the other end is 
drawn out to a long point, bent at a right angle to the body 
of the tube. Insert the point into an ordinary calcium 
chloride tube previously filled and weighed, letting it pro- 
ject a short distance through the cork. This arrangement 
is designed to afford an uninterrupted passage of the water 
from the ignition-tube into the calcium chloride, and allow 
the application of heat very near the extreme point of the 
ignition-tube, to drive all the water into the absorption- 
tube containing anhydrous calcium chloride. Connect 
the cork for the other end of the ignition-tube by 
means of rubber with another tube containing cal- 
cium chloride. This latter is intended to dry the air 
drawn through the apparatus. After the boat containing 
the substance is introduced into the iglition-tube, insert 
the cork, attach the weighed absorption-tube to the point, 
connect the other end of the absorption-tube by means of 
rubber tubing with an aspirator, and proceed to draw a 
gentle current of air through the apparatus. Then apply 
heat to the ignition-tube sufficient to expel the water. 
When this is all drawn into the absorption-tube detach 
the aspirator, allow the apparatus to cool, and weigh the 
absorption-tube. The increase in weight will be equiva- 
lent to the weight of water. From this, calculate the per 
cent as usual. 




CHAPTER IX. 

AMMONIO-FERRIC SULPHATE, OR AMMONIA IRON ALUM* 

FeJSrHi(SOt) 2 .12II 2 0. 
The theoretical composition of the salt is : 

Fe 2 3 16.60 per cent. 

S0 3 33.20 " " 

NH 3 3.52 " " 

H a O 46.68 « " 

100.00 

Select 8 or 10 gms. of crystals which have not lost water 
by efflorescence ; jbreak them into small pieces or coarse 
powder, and keep for analysis in a small, well-corked bot- 
tle. Consult analysis of hydro-disodium phosphate. 

For the determination of the ferric oxide by precipi- 
tation, take as nearly as possible 1 gm. weighed in the 
manner directed in the analysis of potassium alum, or an 
equivalent amount from the solution of a larger quantity, 
if the plan suggested in the analysis of hydro-disodium 
phosphate be adopted. 

If 1 gm. of the solid salt be weighed, dissolve it in 100 
c. c. hot water and 1 c. c. dilute hydrochloric acid. When 
the solution is complete, add ammonia (little by little) 
until the fluid is slightly alkaline, and heat to boiling. 
Then remove the heat and allow the precipitate to settle \. 
decant the clear fluid through a filter, pour upon the pre- 
cipitate 50 c. c. hot water, stir, allow the precipitate to 
settle, and pour the clear fluid through the filter as before. 
Repeat this washing by decantation three times. Then 
transfer the precipitate to the filter with hot water, and 
wash with hot water until the washings give no precip- 
itate when treated with barium chloride solution. Dry 
the precipitate thoroughly, and remove it from the filter 



FEEEIC OXIDE. 41 

by i averting the latter on a clock-glass, and rubbing the 
filter between the finjers. By this means, nearly all of the 
precipitate can be removed from the filter, without any 
danger of loss by brushing. After removing the precip- 
itate as cleanly as possible, burn the filter in a weighed 
crucible, after adding a few drops of nitric acid. When 
the carbon of the filter is completely consumed, brush the 
precipitate into the crucible, and ignite again, keeping it 
covered until all danger of decrepitation is past. Then 
remove the cover, and heat to a bright red heat. After 
heating intensely for some minutes^emove the heat, cool 
the crucible and contents in a desiccator, and weigh. 
From this weight, we obtain % the per cent of Fe 2 3 by de- 
ducting the weight of crucible and filter-ash. If the con- 
tents of the crucible should look black, moisten with a 
few drops of nitric acid, evaporate off |he excess of acid 
carefully, ignite, cool, and weigh again. 

For the determination of the S0 3 acidulate the filtrate 
from the ferric hydrate, and proceed as in the analysis of 
magnesium sulphate. 

To determine the ferric oxide by ignition, introduce 
about 1 gm. of the salt into a previously-weighed crucible, 
and heat gently, and then gradually increase the heat to 
the highest point attainable over a blast-lamp. Cool and 
weigh. Repeat until the weight becomes constant. The 
expulsion of the sulphuric acid can be facilitated by intro- 
ducing into the crucible a piece of pure ammonium car- 
bonate about the size of a pea, covering the crucible,, 
and heating moderately until the ammonium carbonate is 
volatilized, and then strongly, as before. Only ferric 
oxide will be left. Calculate the per cent as usual. 

Of the various methods suggested for the determination 
of iron volumetrically, it is unnecessary to notice more 
than two, namely, that turning upon the use of potas- 
sium permanganate, and that in which potassium bichro- 
mate is employed. 

The first method, known as Marguerite's, depends upon 



42 AMMONIO-FEKKIC SULPHATE. 

the fact that a solution of potassium permanganate, 
which is intensely colored, loses its color when dropped 
into a solution of ferrous oxide, giving up a portion of its 
oxygen, and being decomposed into salts of manganese 
and potassium, until the ferrous is completely converted 
into ferric oxide. The moment this conversion is complete, 
the permanganate imparts color to the fluid. 

The analysis requires a standard solution of potassium 
permanganate, that is, one the value of which is known. 

To prepare this solution, dissolve 6.500 gms. of pure 
crystals of potassium permanganate in 1 litre of distilled 
water, with frequent agitation to insure complete solution, 
if possible. After this, allow the fluid to stand for 24 
hours, and siphon of: into another vessel the perfectly 
clear solution, and close this tightly with a stopper, pref- 
erably of glass. 

There are several methods of standardizing the solution 
of potassium permanganate. Of these, only two will be 
described as reliable, namely, by means of iron, or by oxalic 
acid. Of these, the former (the method proposed by 
Marguerite) is the better one. Use for the purpose fine 
piano-forte wire, which contains 99.7 per cent of iron. 
Dissolve 0.200 gm. of the wire — previously cleaned with 
sand-paper to remove oxide, glaze, and dirt — in a small 
valved flask, with 25 or 30 c. c. of dilute sulphuric acid, 
by the aid of gentle heat ; introducing into the flask, 
with the wire, a small crystal of sodium carbonate, about 
as large as a hemp-seed ; by which means the atmospheric 
air will be displaced by carbonic acid, thus preventing 
the formation of ferric oxide during the solution. When 
the iron is dissolved, allow the flask and contents to cool 
slowly. Do not attempt to hurry the cooling by the ap- 
plication of any cold substance, as the sudden formation 
of a partial vacuum may crush the flask and scatter the 
contents. 

A very convenient kind of valve for the flask in which 
the iron wire is dissolved is the Kroonig valve, described 



FERRIC OXIDE — VOLUMETRIC. 43 

by Mohr in his TitrirrnetJiode (5th ed., 1877, p. 182), 
which is made of a piece of thick rubber tubing, about 
one and a half inches long, one end of which is forced 
over a short glass tube, passing through the cork into 
the neck of the flask, while the other end is closed by a 
short piece of glass rod. The rubber tube has a longi- 
tudinal slit cut in it between the end of the piece of glass 
rod and the glass tube. When the pressure is internal, 
the slit opens, allowing the gas and vapor to escape, and 
it closes when the pressure is external, owing to the cool- 
ing of the flask, thus preventing the entrance of oxygen. 

When the contents of the flask are cool, empty them 
into a large beaker, wash the flask well, adding the wash- 
ings to the solution, and dilute with distilled water to 
about 700 c. c. Then drop in the solution of potassium 
permanganate to be standardized, slowly, from a Gay- 
Lussac burette, w^h constant stirring, until the color 
(which disappears rapidly at first, and then more gradu- 
ally) finally becomes permanent, and remains so for one 
minute. The final color should be a light pink. Note 
carefully the quantity of potassium permanganate used, 
and calculate the value of 1 c. c. thus : Suppose 19.2 c. c. 
of the permanganate solution to be sufficient to oxidize 
the solution of 0.200 gm. of iron wire, or 0.1994 gm. of 
pure metallic iron (as the wire is assumed to contain 99.7 
per cent of-^the latter) ; consequently, 1 c. c. of the per- 
manganate solution will represent 0.01038 gm. of metallic 
iron, or 0.01483 gm. of ferric oxide. (Fres., Quant., §112, 
p. 194.) , , 

To standardize the potassium permanganate solution by 
means of oxalic acid, dissolve 6.300 gms. of pure crystal- 
lized oxalic acid in 1 litre of water. Take 50 c. c. of the 
solution, equivalent to 0.315 gm., and dilute with about 
100 c. c. of water. Add 6 or 8 c. c. pure concentrated 
sulphuric acid, and heat to about 60° C. Add permangan- 
ate solution from a Gray-Lussac burette, until it imparts 
a permanent color, as directed in the previous method. 



44 AMMOTaO-FERRIC SULPHATE. 

By comparing the equations representing the reactions, it 
will be seen that the same quantity of potassium perman- 
ganate is required to oxidize 1 molecule of oxalic acid, 
whose molecular weight is 126, or 2 atoms of iron (in the 
form of monoxide), whose molecular weight is 112. Thus, 
the following represents the oxidation of iron, 

10FeSO 4 +8H 2 SO 4 +K 2 Mn 2 O 8 =5Fe 3 (SO 4 ) 3 +2MnSO,+K 2 SO 4 

+8H 2 0, 

while the next one represents the oxidation of oxalic acid, 

5(H 2 C 2 4 . 2H 2 0)+3H 2 SO,+K 2 Mn 2 8 =: 10CO 2 +2MnSO 4 +K 2 

S0 4 +18H 2 ; 

consequently, 126 : 112=0.315 : 0.280. In other words, 
the 0.315 gm. of crystallized oxalic acid contained in the 
50 c. c. of solution taken as directed above, represents 
0.280 gm. of metallic iron ; and the quantity of perman- 
ganate solution required to oxidize 0.315 gm. of oxalic 
acid will oxidize 0.280 gm. of metallic iron. Suppose 27 
c. c. of the permanganate solution to be required to 
oxidize the 0.315 gm. of oxalic acid, then 1 c. c. will be 
equivalent to 0.01037 gm. of metallic iron, or the result of 
dividing 0.280 by 27. The objection to the use of oxalic 
acid for standardizing potassium permanganate is the 
uncertainty of procuring a perfectly normal acid. 

Whichever method of standardizing the permanganate 
solution is adopted, it is necessary to make more than one 
trial. Should the quantities of permanganate required in 
two trials not differ by more than one tenth of a cubic centi- 
metre, the average of the two may be taken as correct. 
Should a greater difference than this occur, more trials 
must be made to obtain consistent results. 

To determine the ferric oxide, weigh about 4 gms. of 
the ammonio-ferric sulphate, observing the precautions 
suggested before, transfer the substance to a flask holding 
500 c. c, add about 200 c. c. of warm water and 2 or 3 c. c. 
of sulphuric acid. When all is dissolved, cool, and dilute 



FERRIC OXIDE — VOLUMETRIC. 45 

with cool water to the holding mark. Pour the solution 
into a dry beaker, and stir well. Divide the fluid into 
two equal portions, by filling a dry 250 c. c. flask with a 
portion of it, to the holding mark, emptying the flask 
into a reducing bottle, washing the flask, and adding the 
wash-water to the other. If the flasks agree, one half 
will have been transferred to the bottle ; and that remain- 
ing in the beaker, together with that adhering to the 
larger flask, will compose the other half. This, with the 
washings of the beaker and flask, is to be transferred to 
another reducing bottle of similar size. Place in each of 
the bottles a piece of amalgamated zinc, and a piece of 
platinum foil about three quarters of an inch wide and 
four inches long, fill with water to the shoulders, cover 
with watch-glasses, and allow to stand for 24 hours. A 
strong current of gas should be induced by contact 
between the zinc and platinum. When the foil is new, it 
sometimes fails to produce the desired effect. In such a 
case, heat it in a strong solution of potassium hydrate, to 
remove oily matter ; scour the surface with coarse sand, to 
roughen it, and wash it. Should the foil still act badly, 
wet the surface with a little nitro-hydrochloric acid, to re- 
move the polished surface, and wash it with water. The 
zinc used should be amalgamated ; otherwise, as it usually 
contains iron, in dissolving, it will impart iron to the solu- 
tion. Ifc has been found by experiment that amalgamated 
zinc will not give up the iron alloyed with it, to the solu- 
tion to be reduced, until nearly, if not quite, all the zinc is 
dissolved. 

A very good bottle for reducing the ferric oxide is about 
two and a half inches wide, and six inches high, with a 
wide mouth. ' 

After the ferric is reduced to ferrous oxide, empty one 
of the bottles into a large beaker, wash it well with water, 
adding the washings to the solution ; add 2 or 3 c. c. pure 
sulphuric acid, dilute to about 700 c. c, and titrate with 
the permanganate solution in the same manner as directed 



46 AMMONIO-FERKIC SULPHATE. 

for standardizing. The number of c. c. of potassium per- 
manganate used, multiplied by the standard, gives the; 
weight of metallic iron in the solution treated. From this, 
calculate the per cent of ferric oxide. 

The two titrations should not differ more than two 
tenths of a c. c. If they do, another determination should 
be made. 

The other method of determining iron volumetrically, 
by the use of potassium bichromate, is preferable when 
the iron is in hydrochloric acid solution. The following 
equation, 6FeCl 2 +K 2 Cr 2 7 +14HCl=3Fe 2 Cl 6 +2KCl+Cr 2 
C1 6 +7H 2 0, shows that 1 eq., or 295.18 parts of potassium 
bichromate, will convert 6 eq., or 336 parts of iron, to the 
ferric state. Then, if 14.759 gms. of potassium bichromate 
are dissolved in 1 litre of water, 1 c. c. of the solution will 
be equivalent to 0. 0168 gm. of iron. Before using the potas- 
sium bichromate, it should be fused, and cooled under a 
desiccator. The solution of bichromate should be stand- 
ardized with piano-forte wire, as directed before for potas- 
sium permanganate, dissolving 0.200 gm. in 30 c. c. of 
dilute hydrochloric acid. After the solution is cool, pour 
it into a beaker, dilute, and drop in from a burette the 
bichromate solution, constantly stirring with a glass rod. 
The solution will soon turn green. Should it turn brown, 
add more hydrochloric acid. When it becomes dark 
green, place a drop on a white plate, and combine it with 
a drop of solution of potassium ferricyanide, which will 
turn it blue. The solution of potassium ferricyanide 
should not be too strong, or it will give a red precipitate. 
As the oxidation by the potassium bichromate advances, 
the blue color produced by the solution of iron will 
become faint. Note the number of c. c. of bichromate 
solution used, and finish with one only one tenth as strong. 
When the tests no longer produce a blue color, the oxida- 
tion is complete. From the number of c. c. used calculate 
what 1 c. c. is equivalent to. 

For the analysis, reduce the hydrochloric acid solution 



AMMONIA. 47 

of the salt with zinc and platinum, as directed before, 
titre with the bichromate solution, and from the number 
of c. c. used, and the known value of 1 c. c, calculate the 
iron. 

For the determination of the ammonia, weigh about 
1 gm. of the substance, and introduce it into a small tubu- 
lated retort, the tubulure of which is fitted with a tight 
caoutchouc stopper, through which passes a funnel tube, 
provided with a stop-cock. The kind called " thistle 
tube" is the best. The neck of the retort is connected 
with a piece of glass tube, of about the same size, and 
about 10 inches long, by means of a short piece of large 
rubber tube, stretched over both, and firmly tied. The 
glass tube is previously contracted by heat at the end 
nearest the retort, and filled with clean broken glass. The 
other end is fitted with a caoutchouc stopper, through 
which passes a small glass tube, turned down, so as to 
enter a small flask holding about 200 c. c, and passing 
through the stopper nearly to the bottom of the flask. 
This tube has blown on it a large bulb, to prevent reces- 
sion of the fluid from the flask into the retort, in case of 
sudden contraction of the contents of the latter. Through 
the stopper of the flask also passes the point of an 
ordinary calcium chloride tube, filled with broken glass. 
Connect the apparatus, fasten the retort in a holder, with 
the neck inclined slightly upward, at the same time sup- 
porting the tube connected with it and filled with clean 
broken glass, and run into the flask, through the calcium 
chloride tube, enough dilute hydrochloric acid, of about 
1.050 sp. gr. to slightly cover the point of the tube con- 
necting the flask with the retort. Then introduce into the 
retort, through the funnel tube, enough water to dissolve 
the ammonio-ferric sulphate. When this is dissolved, 
run in through the funnel tube 20 or 30 c. c. of a concen- 
trated solution of potassium hydrate, little by little. Then 
close the stop-cock and apply gentle heat, gradually in- 
creasing it, until the fluid in the retort boils. Continue 



48 AMMONIO-FERRIC SULPHATE. 

the boiling for 15 or 20 minutes. When the ammonia is 
expelled, open the stop-cock of the funnel-tube, and draw 
a little air through the apparatus. Then disconnect it, 
wash the tube connecting the flask with the large tube 
attached to the retort into a small porcelain dish, and at 
the same time run water through the calcium tube into 
the flask, and pour the contents into the dish, washing the 
flask well. Add to the contents of the dish an excess of 
platinum tetrachloride, and proceed as directed in the 
analysis of potassium alum. Great caution must be exer- 
cised in igniting the ammonium platino-chloride, or loss 
will be incurred by fine particles of platinum being carried 
ofl by the ammonium chloride. Rose directs that the 
covered crucible be subjected to a low heat for a long time, 
until the filter is completely charred, and that then a 
gradually-increasing heat be applied to the uncovered cru- 
cible, resting on its side, with the lid resting against the 
mouth. The fusion with oxalic acid, and the accompany- 
ing washing, are not required in this case, as the double 
chloride is easily decomposed and reduced to spongy 
platinum by heat alone. From the weight of spongy 
platinum, calculate the per cent of JSTH 3 . 



Note.— In determining iron by Marguerite's method, the presence of HC1 
must be avoided, especially if the solution is at all warm, since the permangan- 
ate under these circumstances will react upon the HC1, affording chlorine. Thus : 
K a Mn 9 8 + 16HC1 = 3KC1 + 2MnCl a + 8H,0 + 10C1. 

Some of the chlorine may convert the ferrous salt present into the ferric, but 
some will usually escape, and the results obtained will consequently be higher 
than the truth. 



CHAPTER X. 

FELDSPAR. 

The following analyses, taken from Dana's Mineralogy 
show the composition of ordinary feldspar : 

Orthoclase. Albite. 

Silica 64.25 65.46 

Alumina 18.80 20.74 

Ferrous Oxide 0.54 

Lime < 1.20 0.71 

Magnesia 0.74 

Soda 2. 40 9. 98 

Potash 12.44 1.80 

Loss by ignition 0. 30 

99.39 99.97 

Pulverize 3 or 4 gms. of the feldspar very line, in an 
agate mortar, and keep the powder in a small, corked 
bottle. Fuse over a blast-lamp 1 gm. of this, carefully 
weighed, in a 2-oz. platinum crucible, intimately mixed 
with about 5 gms. of flux, composed of equal parts of 
potassium and sodium carbonates. The combined car- 
bonates make a much more fusible flux than either alone. 
Examine the crucible occasionally, and, when the contents 
are fused so to flow when the crucible is inclined, move 
it about, after laying the cover aside in a convenient place, 
in such a way as to cause the contents to coat the sides, 
instead of cooling in a solid mass at the bottom, and dip 
it, while still hot, into a beaker of cold water, to about 
half of its depth. Hold it in the water for a few seconds, 
remove it, and, after the lapse of a few more seconds, dip 
it again. Repeat this treatment until the crucible and 
contents are cool enough to immerse without spattering. 
Then lay the crucible on its side in the beaker, which 
should be just large enough to permit this, and have in it 



50 FELDSPAR. 

a sufficient quantity of water barely to cover the crucible. 
Then put the lid also in the beaker, and, after placing a 
convex glass over it, allow it to stand until the fused mass 
is sufficiently softened to be removed from the crucible. 
Owing to the contraction and expansion caused by this 
treatment, the mass can frequently be removed at once 
from the crucible in thin cakes. The object of using as 
small a beaker and as little water as possible is to avoid 
the evaporation, afterward, of an unnecessary quantity of 
fluid. Should the' contents of the crucible be difficult to re- 
move in this way, the operation may be hastened by digest- 
ing on a water-bath, occasionally moving the crucible with 
a glass rod, and replacing the water lost by evaporation. 
Under no circumstances should an effort be made to re- 
move the mass by force, as in doing so there is great 
danger of injuring the crucible. After removing the sub- 
stance from the crucible, place the latter, with the cover, 
in another vessel, pour on them a little dilute hydrochloric 
acid, to dissolve any adhering particles, and wash them 
with water. Pour this solution cautiously into the vessel 
containing the fused feldspar, keeping it covered with a 
glass, to prevent loss by effervescence, and add more 
hydrochloric acid, if necessary, a little at a time. When 
the fluid is acid, heat until all carbonic acid is ex- 
pelled. Then, if the mineral is entirely decomposed, 
transfer all to a casserole, and evaporate on a water-bath 
to dryness. Then heat in an air-bath at a temperature of 
from 100° to 110° C. until the odor of hydrochloric acid 
disappears. Should there be any undecomposed mineral, 
allow it to settle, decant the clear fluid into a casserole, 
and begin to evaporate it as above. In the mean time, add 
some strong hydrochloric acid to the residue, and heat to 
dissolve it if possible. Should it dissolve, add the solution 
to the first one. Should it not dissolve, dilute with a 
little water, filter, wash, and add the filtrate to the prin- 
cipal solution. Dry the insoluble residue, burn it with 
the filter in a platinum crucible, fuse it with about five 



SILICA AND ALUMINA. 51 

times its weight of mixed carbonates, as in the first case, 
and treat as directed above. Repeat the treatment until 
the feldspar is all decomposed. Undecomposed mineral 
can be detected by the rapidity with which it settles to 
the bottom of the fluid, and by feeling hard and gritty 
when pressed by a glass rod, while separated silica rises 
readily in the solution when agitated, settles slowly, and 
offers no resistance to the rod. After the mass is thor- 
oughly dried, moisten it with 20 c. c. dilute hydrochloric 
acid, heat at a temperature just below boiling for 20 or 30 
minutes, and dilute with 50 c. c. hot water ; every thing 
should now be in solution except the silica. Now filter 
out the silica, wash it with hot water until the washings 
give no reaction for chlorine, when treated with silver 
nitrate, and dry the precipitate on the filter, at a temper- 
ature of from 100° to 110° C. When the silica is perfectly 
dry, invert the filter in a weighed platinum crucible, stand- 
ing on a sheet of glazed paper, roll the filter gently 
between the fingers in such a way as to remove the con- 
tents from the paper to the crucible, and, without lifting 
the filter from the crucible, fold it and press it carefully 
down upon the silica. After brushing into the crucible 
any particles that may have fallen on the paper, put on the 
cover, and ignite at first at a heat not more than sufficient 
to char the paper. Continue the low heat as long as 
smoke emerges from the crucible. After all volatile 
matter has been expelled, incline the crucible on the sup- 
port, and gradually raise the heat to the highest point 
attainable by means of a good burner, keeping the cover 
on for a few minutes. Finally, remove the cover, and con- 
tinue heating until the carbon of the filter is consumed 
and the silica is white. Then cool the crucible and con- 
tents in a desiccator, weigh, and calculate the per cent of 
silica, which still retains, perhaps, a little alumina. After 
weighing, moisten the contents of the crucible with pure 
concentrated sulphuric acid, add about 1 gm. of ammonium 
fluoride, which leaves no residue after ignition, incline the 



52 FELDSPAR. 

crucible on the support, replace the cover, and apply the 
heat of a burner in such a way that the flame will strike 
the edge of the crucible and lid. When the sulphuric 
acid is expelled, heat the whole crucible strongly, cool, and 
weigh it. Repeat this treatment until the crucible ceases 
to lose weight. The loss represents silica expelled as 
silicon fluoride. If any thing remains in the crucible, 
fuse it with a little acid potassium, or sodium sulphate, 
cool, moisten with sulphuric acid, and heat again, until 
the mass becomes fluid. Finally, cool and dissolve in 
water, and add the solution to the filtrate from the silica. 

Rapid ignition in the first instance, will cause loss of 
silica, as its particles, being very minute and light, are 
liable to be carried off by the gases expelled from the 
filter-paper by combustion, and also by the vapor of the 
water remaining in the silica itself after drying, since all 
moisture can not be expelled from it by drying at a 
temperature which will not destroy the fibre of the filter. 

To determine the alumina, add to the filtrate from the 
silica, ammonia until the fluid is slightly alkaline, and pro- 
ceed as directed in the analysis of potassium alum. 

If there be any oxide of iron in the feldspar, it will be 
found in the precipitate of alumina, in which case fuse 
the ignited precipitate with pure potassium hydrate, pre- 
ferably in a silver crucible, digest the fused mass until it 
is reduced to a pulverized form, and entirely removed 
from the crucible, which is to be washed and removed. 
Digest again, until the alumina is dissolved in the alkaline 
fluid, and only ferric hydrate remains. Filter, wash well, 
dry, ignite, and weigh the ferric oxide. Its weight, de- 
ducted from the known weight of alumina and ferric 
oxide combined, gives the weight of the alumina ; or the 
alumina may be determined directly by acidifying the 
alkaline solution with hydrochloric acid, then making it 
alkaline with ammonia, boiling, and determining the 
alumina as before, as directed in the analysis of potas- 
sium alum. 



FERRIC OXIDE — ALKALIES. 53 

To determine the ferric oxide by titration, fuse the 
ignited precipitate of alumina containing ferric oxide, 
with 6 or 8 times its weight of acid potassium sulphate, 
until the second molecule of sulphuric acid is expelled ; 
cool, add a volume of pure concentrated sulphuric acid 
equal to that of the fused mass, heat again carefully, 
until the contents of the crucible become fluid. Then 
cool, place the crucible in a vessel of hot water, and digest 
over heat until the sulphates are dissolved. Then reduce 
with zinc and platinum, and titrate with potassium per- 
manganate, as directed in the analysis of ammonio-ferric 
sulphate, and calculate the per cent of ferric oxide. If 
this method is adopted, the alumina is, of course, to be 
determined by difference. 

To determine the lime and magnesia, treat the filtrate 
from the precipitate of alumina and ferric oxide as 
directed in the analysis of limestone. 

The best method of determining the sodium and potas- 
sium is that of Professor J. Lawrence Smith (Am. Jour. 
Sci. and Arts, Yol. I., 1871, p. 269) for separating the 
alkalies from silicates. The method is described in his 
own words : "The silicate is to be well pulverized in an 
agate mortar ; for the analysis I take i gm. or 1 gm. ; the 
former is most commonly used, as being sufficient, and 
best manipulated in the crucible used ; a gramme, 
however, may be conveniently employed. The weighed 
mineral is placed in a large agate mortar, or, better, in a 
glazed porcelain mortar, of % to 1 pint capacity. Weigh 
out an equal quantity of granular sal-ammoniac (a centi- 
gramme more or less is of no consequence), put it in the 
mortar with the mineral, rub the two together intimately ; 
after which, add 8 parts of carbonate of lime, in three or 
four portions, and mix intimately after each addition ; 
empty the contents of the mortar completely upon a piece 
of glazed paper, that ought always to be under the 
mortar, and introduce into the crucible. The crucible is 
tapped gently upon the table and the contents settled down. 



54 FELDSPAR. 

"It is then clasped by a metallic clamp in an inclined 
position, or it is placed in the support referred to in the 
latter part of this article, leaving outside about J or f 
inch ; a small Bunsen burner is now placed beneath the 
crucible, and the heat brought to bear just about the top 
of the mixture, and gradually carried toward the lower 
part, until the sal-ammoniac is completely decomposed, 
which takes about 4 or 5 minutes ; heat is then applied in 
the manner suggested, either with the blast or with the 
burner referred to, acting by its own draught, and the 
whole kept up to a bright red heat for about from 40 to 60 
n^nutes. It is well to avoid too intense a heat, as it may 
vitrify the mass too much. The crucible is now allowed 
to cool, and when cold, the contents will be found to be 
more or less agglomerated, in the form of a semi-fused 
mass. A glass rod, or blunt steel point, will most com- 
monly detach the mass, which is to be dropped into a 
platinum or porcelain capsule, of about 150 c. c. capacity, 
and 60 or 80 c. c. of distilled water is added. In the course 
of a longer or shorter space of time, the mass will slake 
and crumble after the manner of lime ; still better, this 
may be hastened by bringing the contents of the capsule 
to the boiling-point, either over a lamp or water-bath. At 
the same time, water is put into the crucible, to slake out 
any small particles that may adhere to it, and, subse- 
quently, this is added to that in the capsule, washing off 
the cover of the crucible also. 

' ' After the mass is completely slaked, the analysis may 
be proceeded with, although, as a general thing, I prefer 
to allow the digestion to continue 6 or 8 hours, which, how- 
ever, is not necessary. If the contents of the crucible are 
not easily detached, do not use unnecessary force, as the 
crucible may be injured by it, but fill the crucible to 
about two thirds of its capacity with water, bring almost 
to the boiling-point, and lay it in the capsule, with the 
upper portion resting on the edge ; the lime will slake in 
the crucible, and then may be washed thoroughly 



ALKALIES. 55 

into the dish, and, as before, the cover is to be 
washed off. 

" We have now, by this treatment with water, the ex- 
cess of lime slaked into a hydrate, and some of the lime, 
combined with the silica and other ingredients of the sili- 
cate, in an impalpable form ; in solution there is the excess 
of the chloride of calcium formed in the operation, and 
all the alkalies originally contained in the mineral as 
chlorides, and all that now remains to be done is to filter, 
separate the lime as carbonate, and we have nothing left 
but the chlorides of the alkalies. To do this I proceed as 
follows : 

" Throw the contents of the capsule on a filter (the size 
preferred for the quantity above specified is one 3 to 3J 
inches in diameter), wash well, to do which requires about 
200 c. c. of water ; the washing is executed rapidly. The 
contents of the filter (except in those cases where the 
amount of the mineral is very small, and there is no more 
for the estimation of the other constituents) is of no use, 
unless it be desired to heat again, first adding a little sal- 
ammoniac to see if any alkali still remains in it, a precau- 
tion I find unnecessary. The filtrate contains, in solution, 
all the alkalies of the mineral, together with some chloride 
of calcium and caustic lime ; to this solution, after it has 
been placed in a platinum or porcelain capsule, is added a 
solution of pure carbonate of ammonia (equal to about 1^ 
gms. is required). This precipitates all the lime as car- 
bonate ; it is not, however, filtered immediately, but is 
evaporated over a water-bath, to about 40 c. c, and to 
this we add again a little carbonate of ammonia, and a 
few drops of caustic ammonia, to precipitate a little lime 
that is re-dissolved by the action of the sal-a-mmoniac on 
the carbonate of lime. Filter on a small filter (2 inches), 
which is readily and thoroughly washed with but a little 
water, and the filtrate allowed to run into a small beaker 
glass. In this filtrate are all the alkalies as chlorides, and 
a little sal-ammoniac ; add a drop of a solution of carbon- 



56 FELDSPAR. 

ate of ammonia, to make sure that no lime is present. 
Evaporate over a water -bath in a tared platinum dish, in 
which the alkalies are to be weighed ; the capsule used is 
about from 30 to 60 c. c. capacity, and during the evapora- 
tion is never filled to more than two thirds its capacity. 
After the filtrate has been evaporated over the water- 
bath to dryness, the bottom of the dish is dried, and, on a 
proper support, heated very gently, by a Bunsen flame, to 
drive off the little sal-ammoniac. It is well to cover the 
ca/psule with a piece of thin platinum, to prevent any 
possible loss by the spitting of the salt after the sal-am- 
moniac has been driven off. Gradually increasing the 
heat, the temperature of the dish is brought up to a point 
a little below redness, the cover being off (the cover can be 
cleansed from any sal-ammoniac that may have condensed 
by heating it over the lamp). The capsule is again 
covered, and when sufficiently cooled, before becoming 
fully cold, is placed on the balance and weighed. This 
weight gives, as chlorides, the amount of alkalies contained 
in the mineral. If chloride of lithium be present, it is 
necessary to weigh quickly ; for this salt, being very de- 
liquescent, attracts moisure rapidly. It not unfrequently 
occurs that the chlorides, at the end of the analysis, are 
more or less colored with a small quantity of carbon, 
arising from certain constituents in carbonate of am- 
monia ; the quantity is usually very minute, and in no 
way affects the accuracy of the analysis. In selecting 
pure carbonate of ammonia for analytical purposes, it is 
well to select specimens that are not colored by the action 
of light. It only now remains to separate the alkalies by 
the known methods." 

The crucible and burner employed by Professor Smith 
in separating the alkalies from silicates are of his own de- 
vising, and excellent for the purpose. A description and 
drawing of them will be found in Crooke' s Select Methods \ 
p. 409, in the chapter on decomposition of silicates. 

To separate the sodium and potassium and determine 



ALKALIES — LITHIUM. 5? 

them, dissolve the combined chlorides (after weighing 
them) in 20 or 30 c. c. of warm water. Should the solu- 
tion be complete, transfer the solution to a small porcelain 
dish> add 3 or 4 drops of hydrochloric acid, and as much 
solution of platinum tetrachloride as contains an amount 
of the salt equivalent in weight to four times that of the 
combined chlorides present, and determine the potassium 
as directed in the analysis of potassium alum. Should 
the combined chlorides not go completely into water solu- 
tion, filter, evaporate the filtrate 'in a platinum dish as 
before, and proceed as directed above. The solution in 
water must be complete. Any insoluble residue can not be 
alkaline chloride, and as the sodium is estimated by dif- 
ference, it would falsify the results. Deduct the weight 
of potassium found, calculated to potassium chloride, 
from the weight of the combined chlorides. The differ- 
ence will be sodium chloride. Calculate the per cent of 
K 2 and Na 2 0. 

Ignite 1 gm. of feldspar, and from loss calculate per cent 
of moisture and organic matter. 

Lithium is sometimes found in feldspar. When such is 
the case, it is to be looked for in the solution of the alka- 
line chlorides. 

Make the solution slightly acid, evaporate to dryness at 
120° C, add a mixture of equal parts of absolute alcohol 
and anhydrous ether, wash into a flask with the same, 
digest for 24 hours, shaking occasionally, decant on a 
filter, and treat with smaller quantities of the mixture of 
alcohol and ether. Finally, wash on the filter, with the 
same mixture, until the residue gives no evidence of the 
presence of lithium before the spectroscope. (Pogg. An- 
nal, 66, 79.) 

As some sodium and potassium chlorides may be dis- 
solved with the lithium chloride, evaporate off the alcohol 
and ether at low heat, just to dryness, and treat the im- 
pure lithium chloride in the same way. Should any res- 
idue of sodium and potassium chloride be left undis- 



58 FELDSPAR. 

solved, filter it out, and add it to the first one. To the 
alcoholic solution add 20 or 30 c. c. of water, and boil out 
the alcohol and ether, add to the solution a sufficient 
quantity of pure sodium phosphate, and enough pure 
sodium hydrate to keep the reaction alkaline, and 
evaporate the mixture to dryness ; pour water over the 
residue, in sufficient quantity to dissolve the soluble salts 
with the aid of a gentle heat, add an equal volume of am- 
monia, digest at a gentle heat, filter after 12 hours, and 
wash the basic phosphate of lithia with a mixture of equal 
volumes of water and ammonia. Evaporate the filtrate 
and washings to dryness, and treat the residue in the same 
way as before. Should any more lithium phosphate be 
obtained, add this to the principal quantity. Dry the pre- 
cipitate, brush it from the filter as perfectly as possible 
into a clock-glass, burn the filter in a weighed crucible, 
add the precipitate, and ignite again, at a moderate red 
heat. Cool and weigh the basic lithium phosphate (Li 3 
P0 4 ). 

Dissolve the residue of sodium and potassium chlorides 
in water, and treat as before for the determination of 
sodium and potassium, when no lithium is present. 



CHAPTER XL 

LIMESTONE. 

The stone may contain lime, magnesia, iron, alumina, 
•silica, carbonic acid, sulphur, phosphoric acid, water, and 
organic matter, also manganese, chlorine, fluorine, alkalies, 
and even other constituents in minute quantities. The 
lime may exist as carbonate or sulphate, the magnesia as 
carbonate or silicate, the iron as sulphide (pyrites) or 
oxide, and the silica as quartz or as silicic acid combined 
with bases. 

The more common constituents, and those required to 
Ibe determined for technical purposes, are lime, magnesia, 
alumina, iron, silica, carbonic acid, phosphoric acid, 
and sulphur. 

For an analysis of this character, dry a few gms. of the 
finely pulverized stone, to constant weight at 150° C, and 
keep it in a stoppered bottle. Weigh 1 gm. of the dry 
powder, transfer it to a small beaker, add 20 c. c. of water, 
«over the beaker with a convex glass, add 5 c. c. of con- 
centrated hydrochloric acid, 1 c. c. of concentrated nitric 
acid, and heat slowly to boiling. Filter, and wash with 
30 or 40 c. c. of hot water, and proceed at once to evapo- 
rate the filtrate and washings over a water-bath. Dry the 
filter and any undissolved residue, ignite them in a small 
platinum crucible juntil the carbon of the filter is entirely 
consumed, add 1 or 2 gms. sodium carbonate, and 0.100 
gm. sodium nitrate, and fuse until the contents of the 
crucible are fluid. Remove the fused mass from the cru- 
cible with water, dissolve off any adhering particles with 
hydrochloric acid, and add the solution to the vessel con- 
taining the principal contents of the crucible, keeping it 
covered to avoid loss by effervescence, also adding more 



60 LIMESTONE. 

hydrochloric acid if necessary to render the solution acid. 
Boil out free carbonic acid, and combine with the principal 
solution on the water-bath. Evaporate all to dryness, 
transfer to an air-bath, and heat at a temperature of about 
110° C. until the odor of hydrochloric acid disappears. 
Then add 1 c. c. of concentrated hydrochloric acid, and 20 
c. c. of water, heat to incipient boiling, dilute with 50 c. c. 
of water, filter, and wash with hot water, until the wash- 
ings show no turbidity when treated with silver nitrate 
(using only 2 or 3 drops of the wash- water at a time, and 
not beginning to test until 40 or 50 c. c. of it have passed 
through the filter). Dry the funnel and contents in an 
air-bath, at a temperature of about 110° C, ignite in a 
weighed crucible (observing the precautions given in the 
analysis of feldspar), cool, and weigh the silica. 

To the filtrate from the silica, add ammonia to alkaline 
reaction, to precipitate the aluminum and ferric hydrates, 
boil out excess of ammonia, allow the precipitate to settle, 
decant the clear fluid on a filter, and, as some lime and 
magnesia may be carried down by the precipitat,e of 
hydrates, dissolve it in the beaker, with as little dilute 
hydrochloric acid as possible, ~re-precipitate by adding a 
slight excess of ammonia, and boiling as before. Filter, 
wash, dry, and weigh the alumina and ferric oxide 
together. Consult analysis of potassium alum, and that 
of ammonia-iron-alum. 

If it be desired to determine the alumina and ferric oxide 
separately, proceed as directed in the analysis of feldspar. 

Should the filtrate and washings from the hydrates ex- 
ceed 100 c. c, concentrate to that bulk, if possible, and 
add 1 c. c. of ammonia. If the ammonia produce a pre- 
cipitate other than aluminum or ferric hydrate, acidify the 
solution with hydrochloric acid, boil for a minute, and 
then make it alkaline again with ammonia. This is done 
to introduce a sufficient amount of ammonium chloride to 
prevent the precipitation of magnesium hydrate. Then 
add 40 c. c. of a solution of ammonium oxalate (pre- 



LIME — MAGNESIA. 61 

pared by dissolving 1 part of the oxalate in 24 parts of 
water), enough to precipitate all the lime as oxalate, and 
convert the magnesia also into oxalate, which remains in 
solution. Fresenius says this excess is absolutely indis- 
pensable to insure complete precipitation of the lime, as 
calcium oxalate is slightly soluble in magnesium chloride, 
not mixed with ammonium oxalate. (See his Experiment 
No. 92, p. 600.) After adding the ammonium oxalate, 
heat just to boiling and allow the fluid to stand undis- 
turbed for some time. After the precipitate has settled 
perfectly, decant the clear fluid through a filter, wash by 
decantation once with about 25 c. c. of hot water, and 
set this filtrate aside as filtrate No. 1. Then dissolve the 
precipitate of calcium oxalate (mixed with a little mag- 
nesium oxalate) in the beaker, with as little hot dilute 
hydrochloric acid as possible. Should any of the precipi- 
tate have passed over on the filter, wash it back into the 
acid solution, dilute, if necessary, to about 50 c. c. with 
hot water, make alkaline with ammonia, add 5 or 6 c. c. 
of ammonium oxalate solution, stir, and allow the precipi- 
tate to settle. When it has perfectly subsided, filter 
through the previous filter, transfer the precipitace to the 
same, wash it thoroughly with hot water, and determine 
the lime as directed in the analysis of calcium carbonate. 

The first filtrate contains the larger portion of the mag- 
nesia, and the second the remainder. (See Fres., Experi- 
ment No. 93, p. 600.) Acidify the second filtrate and wash- 
ings with hydrochloric acid, concentrate to small bulk, and 
add it to the first. Do not attempt to concentrate the first 
filtrate. 

To determine the magnesia, make the combined filtrates 
from the calcium oxalate alkaline with ammonia, if not 
already so, add 30 c. c. of the ordinary solution of hydro- 
disodium phosphate, and determine the magnesia as 
directed in the analysis of magnesium sulphate. 

To insure the recovery of all the magnesium, either 
evaporate the filtrate from the magnesium phosphate to 



62 LIMESTONE. 

dryness, in a platinum dish, bnrn ont the ammonium 
chloride, dissolve the residue in water containing a few 
drops of hydrochloric acid, and proceed as in the first in- 
stance ; or, concentrate to small volume, add 4 or 5 c. c. 
strong nitric acid, evaporate to dryness, add 4 or 5 c. c. 
strong hydrochloric acid, evaporate nearly dry, dissolve 
in water, and determine magnesium as before. 

(See J. Lawrence Smith, in Am. Chem., Yol. III., p. 201.) 

Determine the carbonic acid by one of the methods 
given in analysis of calcite ; or, if the stone contains no 
organic matter, fuse 4 gms. vitrified borax in a platinum 
crucible, cool and weigh, then transfer 1 gm. of pulverized 
and well-dried stone to the crucible, and weigh again. 
Then heat gradually to redness, and continue until all is 
fused ; cool and weigh. The loss of weight is carbonic 
acid. (SeeFres., §139.) 

To determine the sulphur, dissolve 5 gms. in a mixture 
of 15 c. c. of strong hydrochloric acid, 5 c. c. of strong 
nitric acid, and 10 c. c. of water, in a covered casserole, 
heat to boiling, and when effervescence ceases, remove the 
cover, add 10 c. c. strong hydrochloric acid, and evaporate 
to dryness to expel nitric acid. Then add to the dry mass 
1 c. c. of concentrated hydrochloric acid and 50 c. c. of 
water, and heat just to boiling. Filter out any residue, 
and wash with about 50 c. c. of hot water. Nearly neu- 
tralize the nitrate with ammonia, add 2 c. c. of barium 
chloride solution (containing 1 part of the salt in 10 
parts of water), treat the precipitate of barium sulphate 
as in the analysis of magnesium sulphate, and calculate 
the sulphur. 

To determine the phosphoric acid, dissolve 5 gms. of the 
stone in 10 c. c. of strong nitric acid, and 30 c. c. of hot water, 
in a casserole covered with a convex glass. When effer 
vescence ceases, remove the cover, and evaporate to dry- 
ness. To the dry mass add 5 c. c. of strong nitric acid, 
and 50 c. c. of water, and boil. Then filter, wash with 
about 50 c. c. of water, nearly neutralize with ammonia. 



WATER — ORGANIC MATTER. 63 

add 25 c. c. of molybdic acid solution, and allow to stand 
for some hoars in a warm place. Should a yellow precip- 
itate appear, filter it out, and wash it with molybdic acid 
solution (diluted with an equal volume of water). Dis- 
solve the precipitate through the filter into a small beaker 
with the smallest possible amount of dilute ammonia, add 
2 c. c. of magnesium mixture, and proceed as directed in 
the analysis of hydro-disodium-phosphate. Should a 
second precipitate appear in the filtrate from the first pre- 
cipitate of phospho-molybdate, filter it out and treat it in 
the same way. Calculate the per cent of phosphoric acid, 
as in analysis of hydro-disodium-phosphate. 

It is well after dissolving the precipitate of phospho- 
molybdate in ammonia, to let the solution stand for some 
hours, to allow the silica to separate from any silico-molyb- 
date that may possibly be present, before adding the 
magnesium mixture. Should any silica be deposited, by 
the decomposition of silico-molybdate in the ammoniacal 
solution, filter it out, add the magnesium mixture, and 
proceed as above. 

To determine the water, as some may remain after dry- 
ing the limestone at 150° C, proceed as directed in the 
analysis of hydro-disodium phosphate, weighing it after 
absorption in calcium chloride. 

To determine the organic matter the same method can 
be followed as that suggested for the determination of 
carbonic acid, in anhydrous carbonates, by fusion with 
borax. (See Fres., § 139 — II. — c.) The loss of weight will 
be carbonic acid, water, and organic matter. The differ- 
ence between this and the sum of the weights of carbonic 
acid and water previously determined will be the weight 
of organic matter. Of course, the fusion with borax must 
be carefully done, and the determination of carbonic acid 
and water be accurate, to give correct results. 

Another method is, to dissolve 15 or 20 gms. of the 
limestone in dilute hydrochloric acid, heat it gently to 
expel carbonic acid, filter out any undissolved residue 



64 LIMESTONE. 

through ignited asbestos, wash it well with water, dry it, 
transfer it, with the asbestos, to a platinum boat, intro- 
duce the boat into a combustion-tube of hard glass 
containing oxide of copper, and ignite it in a current of 
dry oxygen, absorbing the resulting carbonic acid, and 
from it calculating the carbon, 58 parts of which, accord- 
ing to Petzholdt, correspond to 100 parts of humus. (See 
Jour./. PraM. Chem., LXIIL, 194.) 

To determine barium, strontium, and manganese, evapo- 
rate to dryness the filtrate from the residue used for the 
determination of organic matter, and heat in an air-bath 
at 100° C, until the odor of hydrochloric acid disappears. 
Then moisten with hydrochloric acid, digest with hot 
water, filter, and wash. The residue will consist of 
silica, and perhaps baryta, and strontia in the form of 
sulphates ; while the filtrate will contain the manganese, 
with other constituents of the limestone. 

Expel the silica from the residue with ammonium 
fluoride and sulphuric acid, in the manner described in 
the analysis of feldspar. If any residue remain, fuse 
it with sodium carbonate, digest with hot water, filter, 
and wash well. Barium and strontium will remain on the 
filter as carbonates. Dissolve them through the filter 
with dilute hydrochloric acid, nearly neutralize the solu- 
tion with ammonia, and add a few drops of sulphuric 
acid, and allow to stand for some hours. Should a pre- 
cipitate of barium sulphate, and perhaps strontium sul- 
phate form, filter it out and wash it, and allow the filtrate 
and washings to run into a small flask. Then stop the 
point of the funnel, fill the filter with a strong solution of 
ammonium carbonate, and allow it to stand for 12 hours. 
By this means, the strontium sulphate will be converted 
into carbonate, while the barium sulphate will be 
unattacked. Remove the plug from the point of the 
funnel, allow the fluid to run into the flask with the first 
filtrate, wash with hot water, and run dilute hydrochloric 
acid through the filter into the flask ; the object of using 



STRONTIA — MANGANESE— CHLORINE. 65 

which is to prevent loss by effervescence by the contact of 
the acid with the solution of alkaline carbonate below. 
Finally, wash with, water, dry the filter and contents, and 
determine the barium sulphate as usual. 

To the combined filtrates in the flask add ammonia and 
ammonium carbonate, and if a precipitate of strontium 
carbonate forms, filter it through a very small filter, wash 
with dilute ammonia, dry, ignite, and weigh the 
strontium carbonate. Be careful to clean the filter well, 
and ignite it separately . (See Fres. , §§ 72 and 102. ) 

To the first filtrate from the silica, baryta, and strontia 
add a few drops of nitric acid, boil, dilute, nearly neu- 
tralize with sodium carbonate, add excess of sodium 
acetate, boil and filter out the ferric hydrate, alumina and 
phosphoric acid, wash slightly, concentrate to small bulk, 
filter again if necessary, run the solution, rendered 
alkaline by a few drops of ammonia, into a small flask, 
nearly fill the flask, add freshly-prepared ammonium 
sulphide, cork the flask, and set it aside for 24 hours for 
the manganese sulphide to precipitate. When the man- 
ganese sulphide has entirely settled, decant off the clear 
fluid into a beaker, not on a filter, wash by decantation into 
a beaker 3 or 4 times, with water containing ammonium 
sulphide and a little ammonium chloride, and then on a 
filter with the same. Then transfer the moist precipitate 
to a small beaker, add hydrochloric acid, warm until the 
mixture smells no longer of hydrogen sulphide, dilute 
slightly, filter, and wash carefully. Then heat the fluid 
to boiling, remove the heat, add solution of sodium car- 
bonate until the fluid is distinctly alkaline, boil until the 
carbonic acid is expelled, filter, wash with hot water until 
the washings are not alkaline to test-paper, dry, ignite, 
cool, and weigh the manganous-manganic oxide (Mn 3 4 ), 
and calculate the manganous oxide (MnO). 

To determine the chlorine, dissolve 40 or 50 gms. of the 
limestone in nitric acid, filter, if necessary, and determine 
the chlorine as directed in the analysis of barium chloride. 



66 LIMESTONE. 

To determine the fluorine, dissolve 40 or 50 gms. of the 
limestone in acetic acid, filter, and in the residue determine 
the fluorine, by fusing and proceeding as directed in the 
analysis of calcium fluoride. 

To determine the alkalies, dissolve about 20 gms. of the 
mineral in hydrochloric acid, add chlorine water and heat 
for a short time. Should there be any residue, filter it 
out and decompose it by J. Lawrence Smith's method > 
given in analysis of feldspar. Combine the filtrate,, 
which may contain some alkali, with the main solution. 
Then add ammonia in slight excess, and ammonium car- 
bonate, and allow the solution to stand for several hours ; 
after this, filter, wash, evaporate the filtrate and washings 
to dryness, in a platinum dish, and expel the ammonia 
salts by igniting to a point just below redness. Dissolve 
in water, add solution of barium hydrate, until the fluid 
is decidedly alkaline, filter and wash well, and add to the 
filtrate solution of ammonium carbonate as long as it pro- 
duces a precipitate, allow the fluid to stand for a short 
time, filter out the barium carbonate, and wash it until 
the washings do not render silver nitrate turbid. Then 
evaporate the filtrate in a weighed platinum dish, after 
adding a drop of hydrochloric acid, ignite to faint redness, 
cool, and weigh the mixed chlorides of the alkalies. It is 
well to dissolve in water, and repeat the treatment with 
barium hydrate and ammonium carbonate, and again 
evaporate and weigh. Separate the alkalies, and deter- 
mine them as directed in analysis of feldspar. 



CHAPTER XII. 

CLAY. 

Clay is derived principally from the decomposition 
of feldspar, or rather feldspathic rocks, and varies in 
composition and color, on account of varying quantities 
of feldspar sand (or feldspar reduced to a granular condi- 
tion and not decomposed), quartz in the form of sand, 
lime, magnesia, oxide of iron, and manganese. Some- 
times oxide of titanium and other minerals in small 
quantities are found. 

The kinds of clay more commonly known are common 
brick clay, ordinary pottery clay, slate, fire-clay, and 
kaolin or porcelain clay. The difference between them is 
due less to the character of the constituents than to their 
relative quantity. 

It is sometimes necessary to make a mechanical 
analysis by separation of the coarse from the fine parts. 
For description of methods, and of apparatus, consult 
Jour. f. Prakt. Chem., XLVIL, 241, and Am. Jour. ScL 
& Arts, 3d series, VI., 288. 

For the chemical analysis dry 20 or 30 gms. of the 
finely-pulverized clay at a temperature of 100° C. to con- 
stant weight, and keep the powder in a well-corked bottle. 

The loss of weight in drying will be equivalent to the 
water. 

Fuse 1 gm. of the dry powder with a mixture of equal 
parts by weight of sodium and potassium carbonates, and 
proceed exactly as directed in the analysis of feldspar, 
for the determination of silica, oxide of iron, alumina r 
lime, and magnesia. 

After weighing the silica, expel it by Rose' s method, 
with ammonium fluoride, and test any residue which 
remains qualitatively for titanium. Should any be 



68 CLAY. 

detected, fuse 5 gms. of the feldspar with sodium 
fluoride and acid sodium sulphate, as directed in partial 
analysis of iron ore, bring into cold water solution, add 
excess of potassium hydrate, filter out the precipitated 
titanium dioxide, wash, dry, transfer the precipitate to a 
capacious platinum crucible, burn the filter and add the 
ash, and fuse all with 10 or 12 times the weight of acid 
sodium sulphate. Cool and digest with concentrated sul- 
phuric acid. When the mass is cool, dissolve it in cold 
water, and precipitate the titanium dioxide by boiling. 
(Compare analysis of titaniferous iron ore, Note 7.) 

For the determination of manganese and other con- 
stituents, consult analysis of limestone. 

Determine the alkalies as in analysis of feldspar. 

To ascertain how much of the silica found exists in com- 
bination with the bases of the clay, how much as hydrated 
acid, and how much as quartz sand, or as a silicate 
present in the form of sand, proceed as follows. (Compare 
Fres. Quant. Anal., 5th ed. 1865, §236.) 

Let A represent silica in combination with bases of the 
clay. 

Let B represent hydrated silicic acid. 

Let C represent quartz sand, and silicates in the form of 
sand, e. g., feldspar sand. 

Dry 2 gms. of the clay at a temperature of 100° C, heat 
with sulphuric acid, to which a little water has been 
added, for 8 or 10 hours, evaporate to dryness, cool, add 
water, filter out the undissolved residue, wash, dry, and 
weigh ( A-\-B-\-C). Then treat it with sodium carbonate as 
directed by Rose, p. 923. Transfer it, in small portions at 
a time, to a boiling solution of sodium carbonate contained 
in a platinum dish, boil for some time, and filter off each 
time, still very hot. When all is transferred to the dish, 
boil repeatedly with strong solution of sodium carbonate, 
until a few drops of the fluid, finally passing through the 
filter, remain clear on warming with ammonium chloride. 
Wash the residue, first with hot water, then (to insure the 



SILICA, FREE AND COMBINED. 69 

removal of every trace of sodium carbonate which may 
still adhere to it) with water slightly acidified with hydro- 
chloric acid, and finally with water. This will dissolve 
(A+B), and leave a residue (C) of sand, which dry, ignite, 
and weigh. 

To determine (B) boil 4 or 5 gms. of the clay (previously 
dried at 100° C.) directly with a strong solution of sodium 
carbonate, in a platinum dish as above, filter and wash 
thoroughly with hot water. Acidify the filtrate with 
hydrochloric acid, evaporate to dryness, and determine 
the silica as usual. It represents (B) or the hydrated 
silicic acid. 

Add together the weights of (B) and ,(0), thus found, 
and subtract the sum from the weight of the first residue 
{A+B+O). The difference will be the weight of (A) or 
the silica in combination with bases of the clay. 

If the weight of (A-\~B-\-C) found here be the same as 
that of the silica found by fusion in a similar quantity, in 
the analysis of the clay, the sand is quartz, but if the 
weight of (A-\-B-{-C) be greater, then the sand contains 
silicates. 

The weight of the bases combined with silica to silicates 
can be found by subtracting the weight of total silica 
found in 1 gm. in the regular analysis, from the weight ol 
(A+B+C) in 1 gm. 



CHAPTEE XIII. 

MANGANESE ORE. 

If it is required to determine the amount of metallic 
manganese that an ore will yield, dissolve 1 gm. of the 
ore (finely pulverized, and previously dried by exposure 
in an air-bath, to* a temperature of 100° C. for 6 hours), in 
a mixture of about 10 c. c. of concentrated hydrochloric 
acid, 2 c. c. of strong nitric acid, and 10 c. c. of water, in 
a small flask. When the ore is decomposed, filter out the 
insoluble residue, which should be light colored, and wash 
well. Pour filtrate and washings into a flask, of a capacity 
of at least 1 litre, add a saturated solution of crystallized 
sodium carbonate, little by little, until tho fluid becomes 
dark red in color, but remains clear, thus showing that 
not quite all the free hydrochloric acid is neutralized. 
Then add a solution of about 5 gms. of sodium acetate, 
dilute to 500 c. c. , heat to boiling, and continue boiling for 
o minutes. Then remove the heat, allow the precipitate 
of basic acetates of iron and alumina to settle, filter hot, 
and wash slightly. 

The water required to remove the precipitate from the 
flask to the filter will be sufficient to wash ifc. Begin at 
once to evaporate the first filtrate, and while doing so, dis- 
solve the precipitate in as little hot hydrochloric acid as 
possible, pour the solution back into the flask, repeat the 
precipitation in the same way, filter, and wash moderately. 
Add this filtrate to the first one, and concentrate both to 
700 c. c. if possible. It is better to use a capacious porce- 
lain dish for the purpose. To this concentrated solution, 
add sodium carbonate, until a slight permanent precipitate 
is formed, and then acetic acid until it is dissolved. Heat 
to boiling, remove the heat, add bromine water until the 



MANGANESE. 71 

solution has a decided color, and continue to heat to a 
point just below boiling, until the fluid becomes colorless. 
Remove the heat, allow the precipitate to settle, add a 
little more bromine water carefully, so as not to disturb 
the precipitate, and heat again, as before, until tho fluid 
loses the bromine color. Continue this treatment until 
the bromine no longer produces a precipitate. Filter out 
the precipitate of manganese oxide, wash slightly, and, to 
be sure that the filtrate contains no manganese, neutralize 
it again with sodium carbonate, acidify ic with acetic acid, 
and proceed as before. When the manganese oxide is all 
precipitated, transfer, with a spatula, as much of the 
precipitate as possible from the filters to a small 
beaker, dissolve what oxide may remain on the filters by 
pouring hot dilute hydrochloric acid through them into 
the beaker, and heat to effect solution. Heat the 
solution to incipient boiling, remove the heat, add solution 
of sodium carbonate until the fluid is alkaline, and boil 
until carbonic acid is expelled. Usually, boiling for 5 or 
10 minutes will effect this. Then, filter ou ' the manganese 
carbonate, and wash with hot water until the washings do 
not turn reddened litmus-paper blue. To test this, hold a 
narrow strip of the paper against the point of the funnel, 
so as to bring it in contact with the washings, as they run 
through. Finally, dry the precipitate, ignite it in a 
weighed crucible, cool, and weigh the manganoso-man- 
ganic oxide (Mn 3 4 ), and calculate the manganese. After 
weighing, it is well to ignite the precipitate, and weigh 
again. If the precipitate is very small, it may be ignited 
rolled up in the filter. 

If the ore contains very little iron oxide, the method of 
neutralizing the acid solution with sodium carbonate until 
it becomes dark red, cannot be followed, as there may not 
be sufficient iron to give the color. In such a case, add 
solution of sodium carbonate until a very slight permanent 
precipitate is formed, and then hydrochloric acid, drop by 
drop, until the solution is slightly acid, and, finally, a solu- 



72 MANGANESE 0KE. 

tion of about 5 gms. of sodium acetate, and then proceed 
as directed above. 

If the ore contains silicate of manganese, fu3e with 
sodium carbonate, and then dissolve in acid, and proceed 
as above. 

In all cases where the acid fails to decompose the ore, 
leaving a dark residue, it" is better to decompose the 
residue by fusion, dissolve the fused mass in acid, and add 
the solution to the principal one. 

If the ore is completely decomposed by acid in the first 
instance, only a white, pulverulent, siliceous residue 
should be left. 

The commercial value of manganese ore depends chiefly 
upon the quantity of chlorine it will yield when treated 
with hydrochloric acid. 

By available oxygen is meant the excess of oxygen over 
the 1 atom combined with manganese to form monoxide, 
and, as only half of the oxygen of manganese dioxide is 
available, 16 parts of oxygen are equivalent to 87 parts of 
manganese dioxide, and, as in the decomposition of 1 
molecule of manganese dioxide by hydrochloric acid 2 
atoms of chlorine are liberated, 16 parts of oxygen are 
also equivalent to 71 parts of chlorine. 

To determine the available oxygen, introduce into flask 
" B " of the apparatus described in the analysis of calcite, 
about 3 gms. of the ore, very finely pulverized, and care- 
fully dried at 100° C. The best method of determining 
the quantity of ore taken is that described in the analysis 
of potash alum, by weighing a tube containing pulverized 
and dried ore, shaking out the desired quantity, again 
weighing the tube and determining the weight of ore 
taken by the loss. Introduce also into the flask about 7 
or 8 gms. of neutral potassium oxalate, and as much water 
as will fill it to about one quarter. Fill flasks "A" and 
" C " of the apparatus about one quarter full of pure con- 
centrated sulphuric acid. Put the apparatus together, 
weigh it, and proceed as directed in the analysis of cal- 



AVAIL-ABLE OXYGEN. 73 

cium carbonate, for the determination of carbonic acid by 
loss, drawing about 1 litre of air through the flasks, very 
slowly, by means of an aspirator, not allowing air-bubbles 
to pass faster than 2 per second. The heat generated by 
the union of the water and sulphuric acid is sufficient. 
The difference in the weight of the apparatus, before and 
after the operation, is equivalent to the weight of carbonic 
acid lost. (Fres., §230.) 

The method of calculating the available oxygen is evi- 
dent upon an examination of the equation representing 
the reaction : 
Mn0 9 +K s C 8 04+2H B S0 4 =MnS0 4 +K,S04+2H 8 0+2C0 9 . 

Two molecules of carbonic acid are equivalent to one 
molecule of manganese dioxide, i. e., 88 parts by weight 
of carbonic acid represent 87 parts by weight of man- 
ganese dioxide. Therefore, if the weight of carbonic acid 
is multiplied by 87, and the product divided by 88, the 
quotient will be the weight of manganese dioxide. As 
only one half of the oxygen of manganese dioxide is' 
available, it is calculated by a simple proportion, viz., 
87 : 16= weight of Mn0 2 ; weight of available 0. 

Some ores of manganese contain carbonates, the carbonic 
acid of which must, of course, be removed before the 
analysis is made. If such be the case, introduce the ore 
as before into flask "B," fill it about one quarter full 
with water, add dilute sulphuric acid (1 part acid to 5 
parts water), little by little, until effervescence ceases, and 
the fluid remains acid after boiling out the carbonic acid. 
Then neutralize the excess of acid with sodium or potas- 
sium hydrate, free from carbonic acid, add the usual 
quantity of neutral oxalate, and proceed as before. (Zeit- 
scJirift f. Analyt. Chem., 1, 48.) 

Another method is that known as the iron method. 
Fresenius's directions (p. 512) are to dissolve in a long- 
necked flask, placed in a slanting position, 1 gm. of piano- 
forte wire, and dissolve it in pure concentrated hydro- 
chloric acid; then weigh about 0. 600 gm. of the ore, in a little 



« 



9 



74 MANGANESE ORE. 

tube, drop this with its contents into the flask, and heat 
cautiously until the ore is dissolved. One eq. of man- 
ganese dioxide, or 87 parts, converts 2 eqs. of iron, or 112 
parts, from the state of ferrous to that of ferric chloride. 
When complete solution has taken place, dilute the con- 
tents of the flask with water, allow to cool, rinse into a 
beaker, and determine the iron still remaining in the state 
of ferrous chloride with potassium bichromate. (See 
analysis of ammonio ferric sulphate.) Deduct this from 
the weight of the wire employed in the process. The dif- 
ference expresses the quantity of iron, which has been 
converted by the oxygen of the manganese from ferrous 
to ferric chloride. This difference, multiplied by 87, and 
divided by 112, gives the amount of manganese dioxide in 
the ore. 

Pattinson has suggested a modification of this method, 
fin a paper read before the Newcastle-upon-Tyne Chem. 
Soc, Jan. 27, 1870. His test analyses are very satisfac- 
tory. He directs to dissolve about 2 gms. of clean iron 
wire in a flask holding about 500 c. c, with about 90 c. c. 
of dilute sulphuric acid, made by adding 3 parts of water 
to 1 part of the acid. A cork, through which passes a 
tube bent twice at right angles, is inserted in the neck of 
the flask, and the flask is heated over a gas flame until the 
iron is dissolved. The bent tube is placed so as to dip 
into a small flask or beaker containing a little water. 
When the iron is quite dissolved, 2 gms. of the finely 
pounded and dried sample of manganese ore to be tested 
are put into the flask, the cork replaced, and the contents 
again made to boil gently over a gas flame, until it is seen 
that the whole of the black part of the sample is dis- 
solved. The water in the small flask or beaker is then 
allowed to recede through the bent tube into the larger 
flask, more distilled water is added to rinse out the small 
flask or beaker and bent tube, the cork well rinsed, and 
the contents of the flask made up to about 250 or 300 c. c. 
with distilled water. The amount of iron remaining un= 



HC1 EEQUIKED FOR DECOMPOSITION. 75 

oxidized in the solution is then ascertained by means of a 
standard solution of potassium bichromate. The amount 
the bichromate indicates, deducted from the total amount 
of iron used, gives the amount of iron which has been 
oxidized to the ferric form by the manganese ore, and 
from which can be calculated the percentage of peroxide 
of manganese contained in the ore. Thus, supposing that 
0.250 gm. of iron remained unoxidized, then if 2 gms. of 
iron were taken at first, 1.750 gms. of iron will have 
been oxidized by the ore. Then as 

112 : 87 = 1.750 : 1.359 gm. Mn0 2 , 
which, if 2 gms. of ore were taken for the test, would rep- 
resent 67.95 per cent of Mn0 2 in the ore. 

Standardized solution of potassium permanganate can 
be used instead of bichromate. 

It is frequently of importance to know the amount of 
hydrochloric acid necessary to decompose an ore of man- 
ganese. This can be determined with sufficient accurac 
for commercial purposes, by what is called Kiefer's solu- 
tion. (Ann. d. Chem. u. Pharm., XCIII., 386.) 

To prepare the solution, dissolve 15 gms. recrystallized 
copper sulphate in 100 c. c. of warm water, and add am- 
monia, with stirring, until the basic salt is nearly dissolved. 
Should the point be overstepped, add more copper sul- 
phate, and repeat. Filter the solution, and add the filtrate 
from a burette, with constant stirring, to 10 c. c. of half- 
normal sulphuric acid, until a permanent turbidity is pro- 
duced, and note the number of c. c. used. As 10 c. c. of 
half -normal sulphuric acid is equivalent to 0.365 gm. of 
hydrochloric acid, this, divided by the number of c. c. of 
the copper sulphate solution used, shows the quantity of 
hydrochloric acid represented by 1 c. c. of it. This is 
standard oopper sulphate solution. 

The next step is to prepare a solution of hydrochloric 
acid of 1.1 sp. gr., and to 10 c. c. of it add the standard 
copper sulphate solution, drop by drop, with constant 
stirring, until the fluid becomes slightly turbid. The 




c 

to 



76 MANGANESE OEE. 

number of c. c. of copper sulphate solution used multi« 
plied by the previously ascertained value of 1 c. c. of it, 
gives the quantity of hydrochloric acid in the hydro- 
chloric acid solution of 1.1 sp. gr. 

Then, into a flask, through the cork of which passes a 
tube about 3 feet long, and of about one quarter of an 
inch diameter, and bent slightly from the perpendicular, 
introduce 1 gm. of the manganese ore to be tested and 10 
c. c. of the standardized hydrochloric acid, and heat 
gently until the ore is decomposed, and then more strongly 
for a few minutes until the chlorine is expelled. 

The object of the long tube is to condense the vapor, 
and allow the fluid to run back into the flask. To insure 
this, it is well to wrap it with a wet cloth and keep it cool. 

After the chlorine is expelled, cool the flask, add 25 
c. c. of cold water, filter, and wash with 25 or 30 c. c. of 
cold water. Then to the filtrate add, as before, standard 
opper sulphate solution, until the fluid is slightly turbid. 
The number of c. c. used shows the quantity of free 
hydrochloric acid present. 

The difference between the quantity of hydrochloric 
acid found in 10 c. c. of the solution of 1.1 sp. gr. before 
adding it to the ore, and the quantity in 10 c. c. after 
using it for dissolving the ore, gives the quantity required 
to dissolve 1 gm. of the ore. 

The calculation of the manganese oxides in an ore is 
best illustrated by an example : 

Suppose total Mn = 25.24 per cent and available O = 6 per cent. 
Calculate first the available oxygen to make Mn0 2 

(O) 16 :(Mn0 8 ) 87 = 6:34.62. 
Calculate the Mn corresponding to this : 

(Mn0 2 ) 87 :(Mn) 55 = 32.62 : 20.62. 

Total Mn as above 25.24 

Mn as MnO s calculated above 20.62 

Difference 4.62 per cent Mn 

Calculate this as MnO. It is equivalent to 5.96 per cent, since 
(Mn) 55 :(MnO) 71 = 4.62 : 5.96. 



CALCULATION OF OXIDES. 77 

Calculate MnO a required to combine with this to form Mn 2 8 : 
(MnO) 71 :(Mn0 2 ) 87 = 5.96 : 7.30. MnO + Mn0 2 = Mn 2 3 . 

Mn 2 8 , then, is (MnO = 5.96) + (Mn0 3 = 7.30) = 13.26 per cent Mn,O t . 
Total MnO 3 calculated from available O = 32.62 
Deduct MnO, combining to form Mn 8 8 = 7.30 

Difference = Mn0 8 existing as such 25.32 

Or the ore contains 

Mn 2 O a 13.86 per cent. 

MnO, 25.32 per cent. 





CHAPTER XIV. 

PARTIAL ANALYSIS OF IKON ORE* 
FOR SILICA, IRONj SULPHUR, AND PHOSPHORUS. 

Pulverize 7 or 8 gms. of the ore to impalpable powder 
in an agate mortar, weigh exactly 5 gms. of the powder, 
and mix it carefully, in a large clock-glass, with 25 gms. of 
dry sodium carbonate and 2.5 gms. of sodium nitrate, 
previously pulverized. Introduce about one third of the 
mixture into a capacious platinum crucible, provided with 
a cover, and heat over a strong Bunsen burner until the 
mass ceases to swell in the crucible from the action of the 

ses. Then allow the crucible to cool to a point below 
edness, introduce about the same quantity, and treat it 

the same way. Finally, transfer the remainder to the 
crucible, and, after heating over the Bunsen flame until 
the contents of the crucible become quiet, apply the 
strongest heat of a good blast-lamp until the contents are 
reduced to quiet fusion, or, as w^^ometimes be the case, 
asemi-fu^d mass results, upon wich heat seems to have 
no more effect. Follow the directions given in the 
analysis of feldspar, for removing the mass from the cru- 
cible, and cleansing the latter from adhering particles. 
When that portion of the contents of the crucible, which 
is insoluble in water, has entirely settled, pour off the 
clear fluid into another vessel, add to the residue 20 or 30 
c. c. pure concentrated hydrochloric acid, together with 
the washings of the crucible, and cover, and evaporate on 
a water-bath nearly to dryness. Then dilute with a little 
water ; and should all be now in solution (except some 
separated silica), transfer all to the alkaline water solu- 
tion, cautiously (keeping the vessel covered to prevent 
loss by effervescence), make the fluid acid with hydro- 
chloric acid, if not already so, heat to boiling to expel car- 



IKON — SULPHITE. 79 

Ibonic acid, transfer to a casserole, evaporate on a water- 
bath, and heat in an air-bath. (Compare analysis of feld- 
spar.) Should there be any undecomposed ore after the 
treatment with acid, as directed above, it may be digested 
once more, with concentrated hydrochloric acid, and the so- 
lution added to the first. But if any ore resists this treat- 
ment, filter it out, add the filtrate to the other solutions, 
dry the residue, burn it in a platinum crucible, fuse as 
before, proportioning the flux to the quantity of residue, 
and, after bringing all into solution, proceed as before. 
Should the ore resist this treatment, which is an extreme 
case, dry and fuse the filtered residue in the way directed 
by Hart in OTiem. Gaz., 1855, 458: "Fuse 8 parts of 
borax in a platinum crucible, add to the mass in fusion 1 
part of finely pulverized ore, stir constantly, and keep 
the crucible half an hour longer at a bright-red heat, add 
dry carbonate of soda as long as it causes effervescence, 
then gradually, and with frequent stirring with a 
platinum wire, 3 parts of a mixture of equal parts of 
nitrate of potassa and carbonate of soda, and keep 
the mass a few minutes longer in fusion. Remove the 
mass from the crucible with water, dissolve in hydro- 
chloric acid, and combine with the other solutions ; evapo- 
rate all to dryness on a water-bath, dry in an air-bath, and 
proceed to the determination of the silica as directed in 
the analysis of feldspar. 

Dilute the acid filtrate from the silica to 500 c. c, and 
divide it into 3 portions, the first containing 100 c. c, in 
which the iron and sulphur are to be determined, and the 
other two containing 200 c. c. each, in which the phospho- 
rus is to be determined in duplicate. 

In the first portion, which is equivalent to 1 gm. of the 
ore, precipitate the ferric hydrate, with an excess of am- 
monia, filter, wash until a few drops of the wash-water, 
acidulated with hydrochloric acid, give no reaction with 
barium chloride solution, for sulphuric acid. Dis- 
solve the precipitate in hot, dilute sulphuric acid, divide 



80 IRON ORE — PARTIAL, 

the solution into 2 equal portions, reduce them with, 
amalgamated zinc and platinum in proper bottles, and de- 
termine the iron volumetrically with potassium perman- 
ganate, as directed in the analysis of ammonio-ferric sul- 
phate. If the ore contain titanic acid, it must be re- 
moved before reducing the ferric to ferrous oxide, as the 
titanium dioxide is also reduced to sesquioxide by the 
action of the zinc and platinum, and reoxidized by potas- 
sium permanganate. Consequently, more permanganate 
will be decomposed than is required to raise the ferrous to 
ferric oxide. 

For the method of proceeding in such a case, consult 
analysis of titaniferous iron ore (Note 7). 

After precipitating the ferric hydrate from the portion 
containing 100 c. c, determine the sulphur in the nitrate 
as directed in the analysis of magnesium sulphate. 

The phosphorus is to be determined in each of the 2 
portions of 200 c. c. by either of the following methods : 

First Method. — The ferric oxide, carrying the phosphoric 
acid, is precipitated from the solution by ammonia, fil- 
tered out, and washed moderately (the water required to 
remove the precipitate to the filter being sufficient). The 
walls of the glass, in which the precipitation is effected, 
are washed down by about 25 c. c. of hot concentrated 
nitric acid. To this the precipitate is transferred by 
means of a spatula, with occasional stirring. After re- 
moving from the filter all of the precipitate that can be 
conveniently reached by the spatula, the solution is 
heated, and poured through the filter, and the filter well 
washed with water into a beaker of medium size. By 
this means complete solution is effected in a very short 
time. This solution is now boiled down to very small 
bulk, to remove all chlorine and excess of nitric acid, di- 
luted to a volume of about 100 c. c, and neutralized by 
ammonia to a light mahogany color. To this a sufficient 
quantity of solution of "ammonium molybdate " is 
added, and the whole kept at a temperature just below 



PHOSPHORUS. 81 

boiling for 2 or 3 hours, and then allowed to stand in a 
warn, place for 12 hours longer. In most cases, 25 c. c. of a 
solution so prepared that 1 c. c. is equivalent to 0.001 gm. 
of phosphoric acid will be sufficient. When the precipi- 
tate has settled, it is filtered out and washed with am- 
monium molybdate solution which has been diluted with 
an equal volume of water. The filtrate is again partially 
neutralized with ammonia, warmed, and allowed to stand 
in a warm place for 5 or 6 hours. If any precipitate occur, 
it is filtered out, and treated as before, and the filtrate 
tested again. In rare cases, a third small precipitate 
forms. 

The washed precipitates of phospho-molybdate are dis- 
solved through the filters with dilute ammonia into the 
same beaker, and the filters washed with water. As a 
small amount of ferric oxide, enough to color the filter 
around the edge, if not more, almost invariably remains 
after washing, nitric acid is now poured on the filter, drop 
by drop, allowed to run into the beaker containing the 
ammoniacal solution, the filter washed with a little water, 
4 or 5 c. c. of ammonium molybdate solution added, to 
separate any phosphoric acid that may be held by the 
ferric oxide, and enough more nitric acid to render the 
solution decidedly acid, avoiding however a large excess. 
By this means, the phospho-molybdate is precipitated free 
from iron, which may have been carried down with it pre- 
viously. The acid solution is allowed to stand for a few 
hours in a warm place, until the supernatant fluid is clear. 
It is well, although rarely necessary, to test this fluid 
(after filtering), for another precipitate, by gently warm- 
ing it, and allowing it to stand for a time. The re-precip- 
itated phospho-molybdate is filtered out, washed with 
dilute ammonium-molybdate solution, and dissolved with 
ammonia. To the solution is added enough hydrochloric 
acid to make it acid, about 0.050 gm. of tartaric acid, 
then enough ammonia to render it decidedly alkaline, and 
finally 5 c. c. of "magnesia mixture." The object aimed 



82 IKON ORE — PARTIAL. 

at in adding the hydrochloric acid and ammonia is the 
introduction of a sufficient amount of ammonium chloride, 
to prevent the precipitation of any magnesium salts from 
the magnesia mixture ; while the tartaric acid is intro- 
duced to hold up any trace of iron that maybe in the solu- 
tion. 

After adding the magnesia mixture, the whole is set 
aside in the cold, until the precipitate of ammonio- 
magnesium-phosphate is entirely formed, when it is 
filtered, washed with dilute ammonia, dried, ignited, and 
weighed. Consult analysis of hydro-disodium-phosphate. 
(Also see article by F. A. Cairns, in Am. Chem., Dec, 
1876.) 

Second Method. — Heat the hydrochloric acid solution to 
boiling, remove the heat, and add a saturated solution of 
pure sodium sulphite (little by little), and more hydro- 
chloric acid, if necessary, until the fluid becomes colorless, 
showing that the ferric is reduced to ferrous chloride. 
Then add a little more hydrochloric acid, and boil until 
the odor of sulphurous acid disappears, keeping up the 
volume of fluid by occasional addition of hot water. 
When the odor of sulphurous acid can no longer be 
detected, if the solution should not have acquired a yellow 
tint, add enough potassium permanganate solution to 
oxidize about 0.150 gm. of the ferrous to ferric chloride, 
then saturated solution of sodium carbonate, until a per- 
manent precipitate is formed, and the solution slightly 
alkaline. Then make the solution acid with acetic acid, 
dilute to about 200 c. c, heat to boiling, and continue to 
boil for 8 or 10 minutes ; after which remove the heat and 
allow the basic acetate of iron to settle completely. It 
will carry all but perhaps a slight trace of phosphoric acid 
with it. Filter, and proceed to boil the filtrate for a 
second small precipitate, to insure the recovery of all the 
phosphoric acid. 

Dissolve the first precipitate by pouring hot hydro- 
chloric acid through the filter. Should it fail to dissolve 



PHOSPHORUS. 83 

all tlie precipitate, throw the filter into the acid, and 
digest over heat nntil the solution is complete. To the 
clear solution, after filtering, if necessary, add ammonia in 
excess (without heating), filter out the ferric hydrate, and 
dissolve it by pouring hot nitric acid through the filter. 
The reason for dissolving in hydrochloric acid first, is that 
the basic acetate is apt to contain a quantity of a modifi- 
cation of ferric oxide, very insoluble in nitric acid, but 
which yields readily to hydrochloric, while the ferric 
oxide re-precipitated from hydrochloric acid solution by 
an excess of ammonia is readily soluble in hot nitric 
acid. 

Boil down the nitric acid solution nearly to dryness, in 
order to expel all chlorine, dilute with hot water to about 
100 c. c, nearly neutralize with ammonia, add 25 c. c. 
ammonium molybdate solution, heat to a point just below 
boiling for 2 or 3 hours, and allow to stand in a warm 
place for 12 hours more. After the precipitate has com- 
pletely subsided, filter and wash with solution of am- 
monium molybdate, diluted with an equal volume of 
water. Eeserve the filtrate, which may contain a little 
phosphoric acid, to be used to dilute the nitric acid solu- 
tion of the second precipitate of basic acetate. 

Dissolve the precipitate of phospho-molybdate of am- 
monium through the filter with dilute ammonia, wash the 
filter with 20 or 30 c. c. of water, run through the filter, 
into the ammoniacal solution, enough dilute nitric acid to 
dissolve any adhering oxide of iron, and render the solu- 
tion slightly acid, adding at the same time 4 or 5 c. c. of 
ammonium molybdate solution, and allow all to stand 
until the precipitate brought out by the nitric acid has 
entirely settled. 

This re-precipitation by means of nitric acid is made to 
separate any traces of ferric oxide, which will remain in 
solution in the nitric acid, while the phospho-molybdate 
precipitates, and can, by filtering and washing with dilute 
ammonium molybdate solution, be (usually) entirely 



I 



84 IRON ORE — PARTIAL. 

freed from iron. Set this precipitate, which contains 
nearly all the phosphoric acid, on one side, after filtering 
and washing it with dilute ammonium molybdate until the 
treatment of the second precipitate of basic acetate is com- 
pleted. 

Bring this second precipitate of acetate into nitric acid 
solution, in the same way as the first one, boil it down 
nearly to dryness, dilute with 30 or 40 c. c. of water, 
nearly neutralize with ammonia, and add to it the filtrate 
from the first precipitate of phospho-molybdate, reserved 
for the purpose, together with the filtrate from the re-pre- 
cipitation of the same by nitric acid. By this means, all 
phosphoric acid which may not have been precipitated 
will be in the solution. Should another precipitate appear 
in this solution, after heating it, and allowing it to stand 
as before, treat it in the same manner as the first one. 
Dissolve both precipitates through the filters, which 
should be of the smallest size, into the same beaker, with 
as little dilute ammonia as possible, and wash them with 
15 or 20 c. c. of water. 

Finally acidulate with hydrochloric acid, add about 
0.050 gm. of tartaric acid, make alkaline with ammonia, 
add 5 c. c. magnesia mixture, and allow to stand for 12 
hours, and proceed as in analysis of hydro-disodium phos- 
phate. (Compare Fres., Quant. Anal., § 135, p. 275.) 

Appendix 1. When only the amount of iron in an ore 
is to be determined, thoroughly mix 1 gm. of the ore with 
3 gms. of sodium fluoride, transfer to a large platinum 
crucible, cover with 12 gms. of coarsely powdered acid 
sodium sulphate, and fuse for 20 or 30 minutes. Then 
cool, add concentrated sulphuric acid, fuse to a homo- 
geneous paste, dissolve in water, reduce with zinc and 
platinum, and titrate with potassium permanganate. As 
stated before, titanium, if present, must first be removed. 
(See Am. Jour. Sci., XLV., 178. Clarke.) 

Appendix 2. If titanium alone is to be determined, fuse 
the ore in the same way with sodium fluoride and acid 



TITANIUM. 85 

sodium sulphate, treat with sulphuric acid, bring into 
solution, precipitate the ferric oxide and titanium dioxide, 
and proceed to determine the latter, as directed in Note 7 
of analysis of titaniferous iron ore. 

Note. — Instead of using sodium carbonate alone to effect the disintegration of 
the ore, a mixture of sodium carbonate with potassium carbonate (both dry) 
may be used. The relative proportions should approximate to the ratios of the 
respective molecular weights), i. e., 106 parts Na a C0 8 to 138.2 parts K,CO| (11 to 
14 would be sufficiently close). 

If the ore is very refractory, the flux proposed by Prof. Dittmar (Phil. Soc. of 
Glasgow) {Iron, Jan., 1876, p. 131,orDingl., Polyt. Journ., CCXXI., 450) may be 
used. This is made by fusing together 3 parts of the above mixture of carbonates 
and 2 parts of borax glass, over a good Bunsen burner, until the carbon dioxide 
has been driven off. Pour the melt out upon a clean, cold surface, and when cool 
pulverize it for use ; keep in a tightly corked bottle. Use 5 to 6 parts of this 
flux to one of the ore, and fuse for an hour or two over a burner, stirring from 
time to time with a stout platinum wire. A small amount of alkaline nitrate 
may be added to oxidize sulphides, etc. A very high heat, such as might be at- 
tained with a blast lamp, is to be avoided, since that would cause the borax to 
attack the platinum of the crucible. 

Any flux which may be used should be carefully tested for the presence of 
sulphates, when sulphur is to be determined in the ore. If a flux free from sul- 
phate cannot be obtained, the amount present must be determined and a deduction 
made accordingly. 

I 



CHAPTER XV. 

COMPLETE ANALYSIS OF IRON" OEE. 



Fuse 5 gms. Note 1. 

Solution (a). 

Cr 3 O s ,Fe 2 ,Al 2 3 ,P 2 5 ,Ti0 2 ,MnO, 

CaO,MgO, etc. 



Residue (a). 

Si0 2 ,Ti0 2 , and perhaps Fe 2 8 , 

Note 2. 



Add Na 8 C0 3 and Br. Note 3. 



Precipitate (6). 
Fe 2 ,0 3 ,Al 2 3 ,P 2 5 ,Mn0 2 ,Ti0 2 ,CaO, 
MgO, etc. 



Filtrate (b). 
CrO,. Note 4. 



Dissolve in HC1 and pass H 2 S. Note 5. 



Filtrate (c). 
FeO,Al 8 O t ,P 2 5 ,Ti0 2 ,MnO,CaO,MgO, 
etc. 



Precipitate (c). 
PtS 2 , etc. Note 5. 



Divide into 2 portions. Note 6. 



£ o/ Filtrate (c). 

FeO,Al 8 8 ,P 2 6 ,TiO a ,MnO,CaO,MgO, 

etc. 



£ o/ Filtrate (c). 
Ti0 2 ,FeO. iVbte 7. 






Oxidize and precipitate acetates. Note 8. 



Precipitate (d). 
Fe 8 O s ,Al 8 3 ,P 8 5 ,Ti0 2 . Dissolve in 

HNO s , dilute and divide. Note 9. 
% of Solution of}£ of Solution of 



Precip. (d) 
P 2 5 . Note 10. 



Precip. (d). 
Al 8 3 ,Fe 8 8 ,Ti0 8 , 
P 2 5 . AddNH 4 
HO. Note 11. 



Filtrate (d). , 

MnO,CaO,MgO, etc. Concentrate 

and add Br. Note 12. 

Filtrate (/). [ Precipitate (/). 

CaO,MgO. Note Mn0 2 . JVbfe 12. 

13. | 



Precipitate (g). 
CaO. iVbfe 13. 



Filtrate (g). 
MgO. iVbte 14. 



S. in separate portion. Note 15. 

Co,Ni,Zn. iVbte 16. 

As in separate portion. Note 17. 

Alkalies in separate portion. Note 18. 

Copper. Note 19. 

Water. Note 20. 

Chlorine, fluorine, carbonic acid, organic matter. Note 21. 

Appendix. 



Iron ores, besides the ordinary constituents, such as 



DECOMPOSING THE OKE. 87 

iron, alumina, manganese, lime, magnesia, sulphur, phos- 
phorus, silica, and water, frequently contain titanium, 
zinc, carbonic acid, potassium, and sodium, and occasion- 
ally chromium, copper, nickel, cobalt, arsenic, and or- 
ganic matter, and in some rare cases vanadium, tungsten, 
chlorine, and fluorine, besides other substances in very 
minute quantities. 

Note 1. — Fuse 5 gms. of the ore, pulverized to impal- 
pable powder (well mixed with 25 gms. of anhydrous sodi- 
um carbonate and 5 gms. of sodium nitrate), in a capa- 
cious platinum crucible. Remove the fused mass from 
the crucible with as little water as possible, allow the solid 
matter to settle, decant off the clear fluid into another 
vessel, digest the solid matter with 25 or 30 c. c. of strong 
hydrochloric acid on a water-bath for an hour or two, 
renewing the acid, if necessary, and keeping the vessel 
covered. When all is dissolved, except perhaps some sil- 
ica and titanium oxide, and no undecomposed ore, add 
the residue, together with the clear fluid, to the first water 
solution, and after acidifying with hydrochloric acid, 
evaporate to dryness as usual, for the determination of 
silica. Should there be any undecomposed ore, filter it 
out, wash with water, and dry it. Add the filtrate to the 
first water solution. Then burn the filter and residue in a 
capacious platinum crucible, add 6 or 8 gms. of acid 
potassium sulphate, and fuse for 15 minutes at a tempera- 
ture scarcely above the fusing point of the latter, then 
raise the heat somewhat, so that the bottom of the cru- 
cible may just appear red, and keep it so for 15 or 20 min- 
utes. The fusing mass should not rise higher than half- 
way up the crucible. The mass begins to fuse quietly, 
and abundant fumes of sulphuric acid escape. At the 
expiration of 20 minutes the heat is increased as much as 
is necessary to drive out the second equivalent of sul- 
phuric acid, and even to decompose partially the sulphate 
of iron and chromium. To the fused mass now add 4 or 
5 gms. of pure carbonate of soda, heat to fusion, and add 



8« IRON ORE — COMPLETE. 

in small portions from time to time during an hour, 3 or 4 
gms. of sodium nitrate, maintaining a gentle red heat all 
the while, then heat for 15 minutes to bright redness, 
cool, and treat the fused mass with hot water ; remove it 
from the crucible, allow the solid matter to settle, add the 
clear fluid to the previous solution, digest the residue 
with strong hydrochloric acid, as directed above, and if 
the ore is entirely decomposed, add everything to the 
other fluid. Should there still be undecomposed ore, re- 
peat the treatment. 

(See Fres., Quant. Anal, § 223, p. 524.) 

After entirely decomposing the ore and combining all 
the solutions, evaporate them to dryness, first on a water- 
bath, and then in an air-bath, as usual in the determina- 
tion of silica. When the mass is thoroughly dry, add 10 
c. c. of strong hydrochloric acid, 30 c. c. of water, and 
heat on a water-bath until everything is dissolved except 
silica and titanium oxide. Then dilute with 50 or 60 
c. c. of water, filter, and wash with about 100 c. c. of 5 
per cent hydrochloric acid, 

There will be a residue (a) of silica and titanic oxide, 
and a solution (a) of the remaining constituents of the 
ore. Dry residue (a), and reserve solution (a), to be com- 
bined with the solution resulting from the re-fusion of the 
silica, which always contains a portion of the titanic 
oxide, and usually some ferric oxide, particularly if the 
quantity of titanic oxide in the ore be large. 

Note 2. — Fuse residue (a), containing silica and titanic 
oxide, and perhaps a little ferric oxide, with 10 or 12 
times its weight of acid sodium sulphate, soften the mass 
by heating it in the crucible with concentrated sulphuric 
acid, cool thoroughly, and dissolve in about 400 c. c. cold 
water. Filter out silica, wash with about 100 c. c. of cold 
water, containing 5 per cent of hydrochloric acid, and add 
filtrate and washings to solution (a). Dry, ignite, and 
weigh the residue, which may still contain some titanic 
oxide. Then treat with concentrated sulphuric acid and 



CHROMIUM. 89 

ammonium fluoride, adding a quantity of the latter equal 
in weight to about 8 times that of the silica. After evap- 
orating off the sulphuric acid and igniting gently, cool 
and weigh. Then repeat the treatment until the crucible 
ceases to lose weight. (Compare Rose's directions, in his 
chapter on silicon, p. 874.) The weight of the silica is 
estimated from the loss. 

Should there be any residue left after the treatment 
with ammonium fluoride, fuse it with acid sodium sul- 
phate,- in the manner directed above, bring it into cold- 
water solution, and add it to solution (a), which will then 
contain all the constituents of the ore except silica. 

Note 3. — To solution (a) add sodium carbonate, until it 
is strongly alkaline, and then, without filtering out the 
precipitate, bromine water, until it is deeply colored, stir- 
ring constantly. After this, add 5 or 6 c. c. of pure bro- 
mine, and heat for an hour, with frequent stirring, keep- 
ing it alkaline and gradually increasing the heat until the 
solution boils, and continue to boil gently for another 
hour. The chromic oxide will be oxidized to chromic 
acid. Then filter and wash thoroughly with hot water, 
first by decantation 3 or 4 times, boiling each time with 
a small amount of water, and then on the filter, until the 
wash-water runs through colorless. If there be a large 
amount of chromium in the ore, in order to insure com- 
plete separation of it, wash the mass on the filter back 
into a beaker, with about 200 c. c. of water, and treat 
again with bromine water and 2 or 3 c. c. of pure bro- 
mine, and proceed as before, filtering through the same 
filter. This will insure complete separation of the chro- 
mium from all but traces of the other constituents of 
the ore, with the exception of manganese, which will also 
be found in the filtrate as sodium manganate. 

There will be a filtrate (&), containing all the chromium 
as alkaline chromate, and a precipitate (&), containing the 
principal part of the other constituents of the ore. 

Note 4. — To filtrate (&), containing chromium, man- 



90 IKON ORE— COMPLETE. 

ganese, and traces of other constituents of the ore, add 
nitric acid to partly neutralize, then 3 or 4 gms. ammo- 
nium nitrate, and evaporate until no odor of ammonia is 
perceptible. Then dilute with 100 c. c. of water, filter, and 
wash the residue of manganese sesquioxide, silica, 
alumina, and titanic oxide, dissolve it in hydrochloric 
acid, after removing it from the filter, with a little water, 
dry and burn the filter, and add the ash, together with 
the solution of the residue, to the solution of precipitate 
(b), or the principal solution of the ore. Into the filtrate, 
containing only alkaline chromate, after acidifying it 
with hydrochloric acid, conduct sulphuretted hydrogen 
to saturation to reduce the chromic acid to sesquioxide. 
Allow the sulphur to settle entirely, filter, wash, and in 
the filtrate precipitate the chromic oxide with ammonia. 
(SeeFres., Quant. Anal, § 106, p. 176.) Evaporate the fil- 
trate from the chromium to dryness, ignite the residue, 
together with the precipitate (if any) produced by sul- 
phuretted hydrogen, dissolve any residue that may be 
left in hydrochloric acid, and add the solution to that of 
precipitate (b) or the principal solution of the ore. 

Note 5. — Dissolve precipitate (b) in hydrochloric acid, 
dilute with cold water, and saturate with sulphuretted 
hydrogen, filter, and wash with cold water. Do not heat, 
as otherwise titanic oxide may be precipitated. 

There will be a filtrate (c) and a precipitate (c) y which 
latter may contain platinic sulphide (due to platinum 
takei^ from the crucible by the fluxes), and also sulphides , 
of metals of the higher groups, which, if present in 
sufficient quantity, are to be determined by methods 
which will be explained later. 

Note 6. — Dilute filtrate (c) to 500 c. c, if it does not 
already exceed that volume, and divide it into 2 portions, 
one containing 100 c. c, or one fifth, and equivalent to 1 
gm. of ore, for the estimation of iron and titanium, and 
another containing 400 c. c. , or four fifths, and equivalent 
to 4 gms. of ore, for the estimation of other constituents 



TITANIUM. 91 

Should the solution exceed 500 c. c. and be less than 
1,000 c. c.j dilute to the latter volume, and divide in the 
same proportion. It is not well to concentrate the solu- 
tion, by the aid of heat, as some of the titanic oxide may 
be precipitated, which will necessitate troublesome steps 
to bring it back into solution. 

Note 7. — To one fifth of filtrate (c), representing 1 gm. 
of the ore, add a little potassium chlorate and hydro- 
chloric acid, and boil, in order to oxidize sulphur, and con- 
vert the ferrous into ferric oxide. Then precipitate the 
ferric and titanic oxides by adding pure potassium 
hydrate in excess, filter, and wash with hot water. By 
this means all but traces of the alumina will be held in so- 
lution, and thus separated from the iron and titanium, 
with the latter of which it otherwise might afterward be 
precipitated by boiling. Dissolve the precipitate in dilute 
sulphuric acid, and increase the volume, by addition of 
cold water, to about 500 c. c. Then add ammonia, drop 
by drop, until a permanent precipitate is formed, and sul- 
phuric acid, cautiously, until it is dissolved, and the solu- 
tion made slightly acid. After this, pass sulphuretted 
hydrogen until the solution is colorless, thus reducing the 
ferric to ferrous oxide. Boil for an hour or two, keeping 
up the volume, by the occasional addition of water con- 
taining sulphuretted hydrogen ; allow the precipitate to 
settle, filter, and wash with hot water. Dry the precipi- 
tate, and as some iron may, and probably will, have been 
precipitated with the titanium, fuse with 10 or 12 times its 
weight of acid sodium sulphate, digest with concentrated 
sulphuric acid, bring the mass into solution in cold water, 
nearly neutralize as above, introduce sulphuretted hydro- 
gen, and repeat the precipitation in the same manner as 
before. Finally filter, wash well with hot water, dry, 
ignite, and weigh the titanic oxide. In igniting the pre- 
cipitate, it is well, after burning the filter, and igniting 
the precipitate, to cool the crucible a little, introduce 
•some ammonium carbonate, heat moderately, until the 



92 IR<m ORE — COMPLETE. 

carbonate is volatilized, and then intensely, in order to 
expel the last traces of sulphuric acid. 

Concentrate the nitrates and washings, after adding a 
little hydrochloric acid and potassium chlorate to about 
200 c. c, precipitate ferric hydrate with ammonia, filter, 
wash well with hot water, dissolve the precipitate in hot 
dilute sulphuric acid, boil for some time to expel chlorine, 
add water, introduce into bottles, reduce with amalga- 
mated zinc and platinum, and determine the iron by po- 
tassium permanganate, as directed in analysis of ammonia- 
iron-alum. 

Note 8. — To four fifths of filtrate (c), representing 4 gms. 
of ore, add a little potassium chlorate, and boil, to oxidize 
the ferrous oxide, nearly neutralize with sodium carbonate, 
add about 10 gms. of sodium acetate, and a few drops of 
acetic acid, dilute to 2.5 litres, in a large flask, and heat to 
boiling. Continue the boiling for about 5 minutes, remove 
the heat, allow the precipitate of basic acetates to settle, 
and filter as rapidly as possible, keeping the fluid hot 
while doing so. Should there be much manganese in an 
ore, it is well to dissolve the acetates in hydrochloric acid, 
and re-precipitate, by the same method, as in such a case, 
the acetates are apt to carry with them a small quantity of 
manganese, when the fluid contains much. 

If the oxidation of the ferrous oxide, by boiling with 
potassium chlorate, has not been complete, the red modifi- 
cation of ferric oxide will be precipitated, giving a great 
deal of trouble, as it is apt to run through the filter, and is 
very insoluble. Generally, the danger can be detected in 
time to be avoided, by the appearance of the precipitate 
caused by the sodium carbonate, used in preparing the 
solution for the precipitation of acetates. If the oxidation 
of the ferrous oxide has been incomplete, the precipitate, 
instead of having the ordinary reddish-brown color, will 
be very dark (nearly black). In such a case, acidify with 
hydrochloric acid, add more potassium chlorate, boil for a 
short time, and precipitate the acetates as directed above. 



PHOSPHORUS — ALUMINA. 93 

Note 9. — Dissolve the basic acetates, or precipitate (d), 
in nitric acid, by transferring the precipitate (a little at a 
time) from the filter to the acid, previously heated in a 
medium-sized beaker, stirring until the precipitate goes 
into solution. When all that can be conveniently removed 
from the filter is dissolved, warm the solution, and pour it 
back on the filter, to dissolve the portion adhering to it, 
and wash the filter thoroughly. Dilute the filtrate to 400 
c. c, and divide into 2 portions, one of 300 c. c, for the de- 
termination of phosphoric acid, and another of 100 c. c, 
for that of alumina. 

Note 10. — In three fourths of solution of precipitate {d\ 
containing 300 c. c, and representing 3 gms. of ore, de- 
termine phosphoric acid as directed in partial analysis of 
iron ore by first method. 

Note 11. — In one fourth of the solution of precipitate 
•(d), containing 100 c. c, and representing 1 gm. of ore, 
precipitate the alumina, ferric hydrate, phosphoric acid, 
and titanic oxide together, by means of ammonia in ex- 
cess. (See analysis of potassium alum.) From the per- 
centage value of this precipitate, deduct that of ferric 
oxide, phosphoric acid, and titanic oxide, found elsewhere 
in the analysis. The difference will give the per cent of 
alumina. 

A direct determination of the alumina may be made by 
fusing the ignited precipitate with acid sodium sulphate, 
digesting the fused mass with sulphuric acid, dissolving 
in water, addiug an excess of pure potassium hydrate, and 
warming. By this means, the titanic oxide and the ferric 
oxide (carrying the phosphoric acid with it) will be precip- 
itated, while the alumina will remain in solution. If, now, 
the solution be filtered, acidified with "hydrochloric acid, 
and then made alkaline with ammonia, and boiled, the 
alumina will be precipitated, and can be determined. 
(Fres., Quant. Anal., § 160, p. 361.) Or, fuse the ignited 
precipitate in a silver crucible with potassium hydrate, 
l)oil the mass with water, filter the alkaline fluid contain- 



94 IR<m ORE — COMPLETE. 

ing the alumina from the undissolved titanic oxide, ferric- 
oxide, and phosphoric acid, acidify the nitrate with hydro- 
chloric acid, and precipitate the alumina with ammonium 
carbonate. (H. Rose, Quant. Anal., chapter on Alumina, 
p. 149.) 

Note 12. — Concentrate filtrate (d), or nitrate from the 
acetates, to 100 c. c, if possible, and precipitate the man- 
ganese, by adding a sufficient quantity of bromine, and 
heating. Filter out the manganese dioxide or precipitate 
(f\ wash it moderately with hot water, transfer it with 
the filter (without drying) to a very small beaker, press 
down the filter upon the bottom of the beaker with a glass 
rod, add enough concentrated hydrochloric acid to cover 
the precipitate, and heat. When the manganese dioxide 
is dissolved, dilute with 20 or 30 c. c. of water, filter, and 
wash thoroughly. Heat the filtrate nearly to boiling, add 
excess of sodium carbonate, boil out free carbonic acid, 
filter out the manganese carbonate, wash with hot water, 
dry, ignite the carbonate to tri-mangano tetroxide, and 
calculate the sesquioxide. (See analysis of manganese 
ore.) 

Note 13. — To filtrate (f) from the precipitate of manga- 
nese dioxide, add ammonia until it is slightly alkaline, 
then a sufficient quantity of ammonium oxalate. Boil, 
and allow the precipitate to settle completely. Pour the 
clear fluid through a filter, add to the precipitate 20 or 30 
c. c. hot water, stir, and allow it to settle. Again pour 
the clear fluid through the filter. Then dissolve the pre- 
cipitate in the beaker with hot dilute hydrochloric acid, 
add to the solution 4 or 5 c. c. of ammonium oxalate, and 
make it alkaline with ammonia. Finally, filter into a 
fresh beaker, and wash thoroughly with hot water. Dry 
the precipitate of calcium oxalate, transfer it to a weighed 
crucible, moisten it with concentrated sulphuric acid, 
evaporate off the excess of acid, ignite, and weigh the 
calcium sulphate, and calculate the per cent of lime. 
(Consult analysis of calcium carbonate.) 



MAGNESIA — SULPHUK. 95 

Note 14. — Concentrate the second filtrate, or the filtrate 
from the re-precipitated calcium oxalate to small bulk (after 
acidifying it with hydrochloric acid), make it alkaline 
with ammonia, and add it to the first filtrate from the cal- 
cium oxalate. (Consult analysis of limestone, andFres., 
Quant Anal., § 154.6, p. 349.) 

The combined filtrates constitute filtrate {g). To this, 
if not already alkaline, add ammonia and a sufficient 
quantity of hydro-disodium phosphate, and allow to stand 
in the cold for some hours. When the precipitate of mag- 
nesium phosphate has entirely settled, filter, wash with 
dilute ammonia, dry, ignite, and weigh the magnesium 
pyrophosphate, and calculate the magnesia. 

Owing to the quantity of ammonium chloride and other 
salts introduced into the analysis, by the re-agents used, 
it may be impossible to precipitate the magnesia com- 
pletely. It is advisable, therefore, to treat the filtrate 
from the magnesium phosphate by one of the methods 
prescribed in the analysis of limestone, to recover any 
magnesia which may have been held in solution. 

Note. 15 — In iron ores containing titanium and requir- 
ing the use of sulphates, it is, of course, impossible to 
determine the sulphur in the current analysis. In such 
cases it is necessary to determine it in a separate portion of 
ore. A very good method of fusion for this purpose is one 
devised by Hart, for the decomposition of chromic iron 
ore (Chem. Gaz., 1855, p. 458), and quoted by Fresenius, 
in his Quantitative Analysis, 4th London edition, § 160 : 
' ' Fuse 8 parts of borax in a platinum crucible, add to the 
mass in fusion 1 part by weight of the finely pulverized 
ore, stir constantly, and keep the crucible half an hour 
longer at a bright red heat ; add dry sodium carbonate as 
long as it causes effervescence, then gradually, and with 
frequent stirring with a platinum wire, 3 parts of a mix- 
ture of equal parts of potassium nitrate and sodium 
carbonate, and keep the mass a few minutes longer in 
fusion." Remove the mass from the crucible with water, 



96 IRON OEE — COMPLETE, 

dissolve in hydrochloric acid, and determine sulphur, as 
in partial analysis of iron ore. (See note on p. 85.) 

Note \ 6. — If zinc, nickel, and cobalt are present, they 
will be found in filtrate (d) (or the acetic acid solution, 
after removing the acetates), together with the manganese, 
lime, and magnesia. The best method for separating the 
nickel, cobalt, and zinc from the others, is that suggested 
by Gibbs, in the Am. Jour, of Sci. and Arts, Jan. 7, 
1865: Add a few drops of acetic acid to the solution, 
boil, pass a rapid current of sulphuretted hydrogen for 
half an hour, and continue the boiling while doing so. 
Gibbs states that every trace of nickel, cobalt, and zinc 
will be precipitated as sulphides, while the whole of the 
manganese (as well as the lime and magnesia) remains in 
solution. These are to be determined as directed in notes 
12, 13, and 14. If large quantities of manganese and zinc 
be present, as in the case of Franklinite ores, it is well to 
dissolve the precipitated sulphides, and after adding a 
sufficient quantity of sodium acetate and acetic acid, 
repeat the precipitation as above, as some manganese may 
be precipitated with the zinc. The writer has had it to 
occur in the analysis of Franklinite. Under ordinary cir- 
cumstances, the re-precipitation is unnecessary. Dissolve 
the precipitated sulphides in aqua regia, convert the 
metals into double cyanides, by means of pure potassium 
cyanide, and precipitate the zinc by potassium sulphide, 
as recommended by Wohler. (See analysis of German 
silver.) In the filtrate from the zinc, determine the 
nickel and cobalt as directed in the analysis of nickel 
ore. 

Note 17. — Fuse 2 or 3 gms. of the ore with 10 times the 
weight of a mixture of equal parts of sodium carbonate 
and nitrate, extract the sodium arsenate by boiling with 
water, filter, acidulate the alkaline filtrate with hydro- 
chloric acid, and precipitate the arsenic with sulphuretted 
hydrogen. Dissolve the sulphide by digesting with hydro- 
chloric acid and potassium chlorate, make the solution 



COPPER — WATER, ETC. — APPENDICES. 97 

alkaline with, ammonia, and determine the arsenic, as 
directed in the analysis of arsenic ore. 

Note 18. — To determine sodium and potassium, fuse 
1 gm. with precipitated calcium carbonate and ammonium 
chloride, and proceed as directed in analysis of feldspar, 
bj J. Lawrence Smith' s method. 

Note 19. — If the ore contain copper in considerable 
quantity, it may be determined in precipitate (c), or, if 
the quantity be very small, in a larger and separate por- 
tion of ore, by methods described in analysis of copper ore. 

Note 20. — Water existing in the ore as mere hygro- 
scopic moisture, is determined by drying 2 or 3 gms. of the 
finely powdered ore to constant weight at a temperature 
of about 110° C. 

If the water be a constituent part of the ore, as in the 
case of limonite, determine it, as directed in analysis of 
hydro-disodium phosphate. 

Note 21. — For the determination of chlorine, fluorine, 
carbonic acid, and organic matter, consult analysis of 
limestone. 

Appendix 1. — Analysis of iron ore containing titanium, 
but no chromium : 

Fuse 5 gms. of the finely powdered ore with 25 gms. of 
sodium carbonate, and 5 gms. of sodium nitrate, and treat 
the fused mass as directed in Note 1. Follow the direc- 
tions given in the same note for effecting complete decom- 
position of the ore, and for filtering, washing, and drying 
residue (a). 

There will be a solution (a) and a residue (a). Treat 
residue (a) as directed in Note 2. Omit the treatment of 
solution (a) with sodium carbonate and bromine, as 
directed in Note 3, pass sulphuretted hydrogen through 
solution (a), and proceed as directed in Note 5 for the 
treatment of the solution of precipitate (b). The rest of 
the analysis is made in the same manner, as that of iron 
ores containing chromium as well as titanium. 

Appendix 2. — Analysis of iron ore containing neither 
titanium nor chromium : 



98 IKON OEE — COMPLETE. 

Fuse 5 gms. of the ore with sodium carbonate and 
nitrate, and proceed as directed in Note 1 for the treat- 
ment of the fused mass. Probably, if the ore has been 
properly pulverized, there will be no undecomposed ore. 
Should there be any, dry and ignite the residue, and fuse 
it again with sodium carbonate and nitrate, and not with 
sulphate, as otherwise it will be necessary to determine 
the sulphur in a separate portion of ore. 

There will be, as in the analysis of titaniferous iron ore 
containing chromium, a solution (a) and a residue (a). 

Dry, ignite, and weigh residue (a), expel the silica with 
ammonium fluoride and sulphuric acid, and estimate the 
per cent of silica by the loss of weight. Should there be 
any residue left in the crucible, it will be entirely ferric 
oxide. Bring it into solution as directed in Note 2, by 
fusion with sodium sulphate. Divide this solution into 2 
parts, one of one fifth, and another of four fifths. From 
the part containing one fifth, precipitate the ferric hydrate 
by ammonia, filter, dissolve the precipitate in sulphuric 
acid, and combine the solution with that of the ferric hy- 
drate obtained from one fifth of solution (a). Add the 
part containing four fifths to four fifths of solution (a). 
Omit the treatment of solution (a) with sodium carbon- 
ate and bromine (as directed in Note 3), and at once divide 
it into two parts, one of one fifth for iron and sulphur, 
and another of four fifths for the determination of the other 
constituents of the ore. In the part containing one fifth, 
precipitate the ferric hydrate by ammonia, filter it out, 
dissolve it, together with the small precipitate obtained 
from one fifth of the residue left in the crucible after ex- 
pelling silica, and determine the iron as usual, by titration 
with potassium permanganate. In the filtrate from the 
precipitate of ferric hydrate, in one fifth of solution (a), 
determine the sulphur. (See partial analysis of iron ore.) 

Through the portion of solution (a) containing four 
fifths (combined with four fourths of the solution of the 
residue left after expelling silica), pass sulphuretted 
hydrogen. (See Note 5.) Then oxidize the filtrate, and 



VANADIUM — TUNGSTEN. 99 

proceed as directed in Note 8. After this, continue the 
analysis, as directed for that ore, containing both 
chromium and titanium. 

Appendix 3. — Vanadium and tungsten have been found 
in iron ores. 

To determine vanadium, fuse 15 or 20 gms. of the ore, in 
the form of impalpable powder, with one third its weight 
of potassium nitrate. Then cool, and remove the mass 
from the crucible by digesting with water as usual, and 
mix carefully with nitric acid, leaving the solution slight- 
ly alkaline. Filter, and add to the filtrate barium 
chloride as long as it produces a precipitate. Filter out 
the baryta salts ; to the still moist precipitate add dilute 
sulphuric acid in slight excess, boil and filter. Then neu- 
tralize the filtrate with ammonia, concentrate, and add a 
fragment of ammonium chloride. As the ammonium 
chloride dissolves, ammonium vanadate is precipitated, as 
a crystalline powder. Allow it to settle, filter it out, and 
wash it with solution of ammonium chloride. Dry the 
precipitate, and heat it to red vanadic acid, which fuses, 
and cools to a crystalline mass. (H. Rose, Quant. Anal., 
pp. 498, et sea.) 

To determine tungsten, fuse 15 or 20 gms. of the finely 
pulverized ore with four times its weight of sodium carbon- 
ate. (Do not use nitrate.) Digest the fused mass with 
water, filter, and wash. Saturate the solution carefully 
with nitric acid, so that it will slightly redden litmus 
paper, after the carbonic acid has been expelled. Let it 
stand 24 hours in a moderately warm place, and then, but 
not before, add solution of mercurous nitrate as long as it 
produces a precipitate. Let the precipitate settle, collect 
it on a filter, and wash with water, to which has been 
added a little mercurous nitrate. This is necessary to pre- 
vent the liquor from running through the filter turbid. 
After drying, burn the precipitate under a chimney with a 
good draught. After calcination, tungstic acid remains 
pure. Repeat the ignition to constant weight. (See H* 
Rose, Quant. Anal., p. 488.) 



CHAPTER XVI. 

SLAG. 

Fuse 5 gms. of the finely-pulverized slag with 25 gms. 
of anhydrous sodium carbonate and 2 gms. of sodium 
nitrate, and proceed to the determination of the silica, as 
in the analysis of feldspar. 

Dilute the filtrate from the silica, with water, to 500 c. c, 
and divide it into 2 portions, one of 100 c. c, and equiva- 
lent to 1 gm. of the slag ; the other of 400 c. c, and equiv- 
alent to 4 gms. 

In the portion containing 100 c. c, precipitate the ferric 
oxide with ammonia, filter and wash out all sulphuric acid, 
dissolve the precipitate in hot dilute sulphuric acid, trans- 
fer to bottles, reduce with zinc and platinum, titre with 
standardized potassium permanganate, determine the iron 
and calculate it to ferrous oxide. Acidify the filtrate from 
the precipitate of ferric oxide slightly with hydrochloric 
acid, and determine the sulphur, as in the analysis of 
magnesium sulphate. 

Saturate the portion containing 400 c. c. with sulphu- 
retted hydrogen, filter, wash well with water, and deter- 
mine any metals that may be present, by the methods 
given in their respective analyses^ with the exception of 
platinum, a small quantity of which may be introduced 
into the analysis by the action of the fluxes on the cru- 
cible. 

Boil the filtrate from the precipitate produced by sul- 
phuretted hydrogen, with about 0.500 gm. of potassium 
chlorate, to oxidize sulphur of the sulphuretted hydrogen, 
and raise the ferrous to ferric oxide, and continue to boil 
until free chlorine is expelled. Then add saturated solu- 
tion of sodium carbonate until the fluid is slightly alka- 
line, acidify it with acetic acid, and boil to precipitate 



101 

basic acetates. (See analysis of manganese ore.) Heat 15 
or 20 c. c. of nitric acid in a beaker, and by means of a 
spatnla add to it the precipitate of acetates (a little at a 
time), with, frequent stirring. When all that can be con- 
veniently reached by the spatula is removed, pour the hot 
solution through the filter, and wash it well. Dilute the 
solution to 400 c. c, and divide it into 2 portions, one of 
100 c. c, and the other of 300. 

In the portion containing 300 c. c, and equivalent to 3 
gms. of slag, determine the phosphoric acid, as in analysis 
of iron ore by the first method, if the quantity of iron 
present be small, or by the second method, if it be large. 

In the portion containing 100 c. c, and equivalent to 1 
gm. of slag, precipitate alumina, ferric oxide, and phos- 
phoric acid together, b\ means of ammonia, and proceed 
as in the analysis of pota ssium alum . 

From the weight of this precipitate, after ignition, 
deduct the sum of the weights of phosphoric acid and 
ferric oxide, found previously. The difference will be the 
weight of the alumina. 

Concentrate the filtrate from the basic acetates to small 
volume, precipitate with bromine, and determine the man- 
ganese as in the analysis of manganese ore. Calculate the 
manganese to manganous oxide. 

In the filtrate from the precipitate of manganic oxide, 
determine the lime and magnesia as in the analysis of 
limestone. 

Determine alkalies as in the analysis of feldspar. 



CHAPTER XVII. 

CAST-IRON, STEEL, AND WROUGHT-IRON. 

The analysis of cast-iron covers the ground entirely, as 
the constituents of steel and wrought-iron are determined 
in the same manner as those of cast-iron. A large number 
of substances may be found in the iron, either combined 
or mixed with it. Those usually determined in cast-iron 
are combined carbon (or carbon chemically combined with 
iron), uncombined carbon (or carbon existing in the form 
of graphite), silicon, phosphorus, sulphur, manganese, 
and copper. Besides these, the iron may contain nitro- 
gen, potassium, sodium, lithium, calcium, magnesium, 
aluminium, chromium, titanium, zinc, cobalt, nickel, 
tin, arsenic, antimony, vanadium, molybdenum, barium, 
slag, and, in rare cases, traces of other metals. Iron is 
usually estimated by difference, that is, the difference 
between 100 and the sum of the per cents of the other 
substances found. In many cases, however, it is neces- 
sary to determine it directly. Owing to the large number 
of substances that may be found in cast-iron, it is better 
to make the analysis on a number of separate portions, to 
avoid complexity. 

For the determination of iron, barium, and titanium, 
weigh 10 gms. of the material in the form of borings, 
filings, or chips, transfer to a capacious casserole, cover 
with a convex glass, add 300 c. c. of water, containing 30 
c. c. of concentrated sulphuric acid, heat on a water-bath 
until the iron is dissolved, remove the cover, and heat 
over a burner until copious fumes of sulphuric acid are 
evolved. Cool, dilute with about 200 c. c. of cold water, 
filter, and wash with about the same quantity of cold 
water. Dry the residue (which may contain graphitic 
carbon, iron, barium, and titanium, besides silica), ignite 



IRON — BARIUM — TITANIUM. 103 

it, together with, the filter, in a platinum crucible, add 7 
or 8 gms. of sodium carbonate and 3 or 4 of sodium 
nitrate, and fuse over a Bunsen burner, until the contents 
of the crucible are fluid. By this means the carbon will 
be consumed. Then remove the fused mass from the cru- 
cible with water, acidulate with hydrochloric acid, add 8 
or 10 drops of sulphuric acid, and evaporate to dryness, 
as usual, for silica. To the dry mass add about 1 c. c. of 
concentrated sulphuric acid, and 40 or 50 c. c. of water, 
filter out and thoroughly wash the silica, which may con- 
tain barium sulphate and titanic oxide, and add the fil- 
trate to the principal solution, which will now contain all 
the iron and tlie larger part of the titanium. Dry the sili- 
ceous residue, treat it with acid sodium sulphate and sul- 
phuric acid, as directed in " complete analysis of iron 
ore," Note 2, dissolve in cold water, filter, wash thor- 
oughly with cold water, and add the filtrate to the princi- 
pal solution, which will now contain all the iron and titan- 
ium, while the residue will contain silica and barium. 
Dry the residue, ignite it in a platinum crucible, cool, and 
weigh. Expel the silica with v ammonium fluoride and 
sulphuric acid. The loss will be silica. Determine it as a 
check. Fuse the residue with sodium carbonate, digest 
the fused mass with hot water, transfer it to a filter, and 
wash with hot water, until the sodium sulphate and excess 
of flux is washed out. The barium will remain on the 
filter as carbonate. Dissolve it through the filter with 
dilute hydrochloric acid, precipitate barium sulphate as 
usual, and calculate the barium. 

Precipitate the ferric and titanic oxides with pure potas- 
sium hydrate, and proceed to determine the titanium as 
directed in Note 7 of " complete analysis of iron ore." 

Treat the filtrate as directed in the same note, and in 
one tenth determine the iron by titration with potassium 
permanganate, as usual. 

If no titanium be present, the determination of iron 
may be made on 1 gm., which is to be treated in the man- 



104 CAST-IKON, STEEL, ETC. 

ner directed above, with the exception of the steps taken 
for the separation of titanium. Of course, the treatment 
for the determination of barium will be unnecessary. 

The presence of hydrocarbons in the solution renders it 
impossible to determine iron accurately with potassium 
permanganate. Consequently, it is advisable, even after 
evaporating to fumes of S0 3 , as above, to precipitate the 
f eriic hydrate, wash it well, and re-dissolve it in sulphuric 
acid. 

A great many methods for the determination of carbon 
in iron and steel have been proposed and used, of which 
only a few can be noticed here. Usually, all that is re- 
quired to be known is the total amount of carbon. In 
iron and steel containing no graphite this is all combined. 

Where the per cent of carbon present in both conditions 
(that is, as combined with the iron as carbide and uncom- 
bined or graphitic) is required, the total carbon is deter- 
mined in one portion of the iron, and the graphite in 
another. The difference between the amount of total 
carbon, and that of the graphite, gives the amount of 
combined carbon. 

To determine total carbon, Weyl dissolves a piece of the 
iron, previously weighed, suspended in dilute hydro- 
chloric acid, by means of platinum pincers, or wire, from 
the positive pole of a weak galvanic battery (1 Bunsen 
element), the platinum foil forming the negative electrode 
being also immersed in the fluid. The strength of the cur- 
rent is regulated by 'increasing or diminishing the distance 
between the piece of iron or steel and the platinum foil, 
which form the two electrodes. No ferric chloride should 
be formed. Should it be, it can be detected by the 
yellowish color of the solution descending from the iron. 
To prevent this, the distance between the electrodes is in- 
creased. When a sufficient quantity of the iron has been 
dissolved, which will require 10 or 12 hours, the carbon is 
removed from the undissolved portion of the iron, by 
brushing it off and washing it into the solution. The lumpK 



TOTAL CARBON. 105 

of iron is then dried and weighed, and the quantity taken 
determined by the loss of weight. The carbon is then col- 
lected in a funnel, the neck of which is lightly plugged 
with a little ignited asbestos, washed moderately with water, 
dried, mixed with copper oxide, and burned in a current 
of oxygen gas. The resulting carbonic acid is absorbed in 
soda-lime, and the carbon calculated. (See Fres., Quant. 
Anal., % 229, p. 536, and also Crookes's Select Methods, 
p. 76.) For the method of making the combustion, see 
" Sugar (Ultimate Analysis)." 

Weyl's method is applicable to the determination of 
carbon in hard iron, that cannot be readily broken into 
small fragments, or be reduced to powder, by the drill 
or file. As carbon is sometimes carried by the mechanical 
working of the current, particularly in the case of steel, 
from the positive to the negative electrode, it is prudent 
to interpose a diaphragm of bladder or parchment paper. 

Regnault's method, for which consult Fres., Quant. 
Anal., 4th London Ed., § 249 ; and Boussingault's, for 
which see Crookes' s Select Methods, p. 77, can be used only 
in the case of iron that is susceptible of being reduced to 
a state of very fine division. 

R. E. Rogers and Wm. B. Rogers proposed the use of 
copper sulphate to dissolve the iron, and the oxidation of 
the residual carbon by means of potassium bichromate and 
sulphuric acid, absorbing the resulting carbonic acid in 
soda-lime or potassium hydrate. (See Am. Jour. Sci. and 
Arts, 1848.) 

Ullgren afterward proposed the same method, using 
chromic acid instead of potassium bichromate. (See Fres., 
Quant. Anal., 4th London Ed., § 249.) 

In a paper published in the Chemical News of May, 
1869, Arthur Elliott proposed a modification of Rogers's 
and Ullgren' s methods. His process is among the best in 
use. It has given very satisfactory results, in a great 
many analyses, made by the writer, of iron, steel, 
graphite, and coal of various kinds. For a few experi- 



106 

ments, giving the time occupied and the per cent of 
carbon obtained, by this method, and combustion in 
oxygen, see a paper published by the writer in the Am. 
Chemist of October, 1871. 

Add to 2 or 3 gms. of borings, filings, or very small 
fragments (in a small beaker) 50 c. c. of a solution of neu- 
tral copper sulphate (containing 1 part of the salt in 5 
parts of water), and heat gently for about ten minutes. In 
order to obtain the neutral sulphate, dissolve the recrystal- 
lized salt (as sold by the dealers) in water, add a small 
quantity of copper oxide, boil until the copper sulphate 
begins to crystallize, filter out the excess of oxide, and 
concentrate the solution until it is completely crystallized. 
Dry the crystals by draining off the water, should 
there be any, and pressing them between layers of bibu- 
lous paper, and dissolve them in water in the proportion 
stated above. After heating the solution of copper sul- 
phate, containing the iron, about ten minutes, by which 
means the iron will be dissolved and copper precipitated, 
add 20 c. c. of a solution of copper chloride (containing 1 
part of the salt in 2 parts of water), and 50 c. c. of con- 
centrated hydrochloric acid, and heat to a point just be- 
low boiling, with frequent stirring, until the precipitated 
copper is dissolved, leaving the carbon free. Filter it out 
through a funnel, made of large glass tubing. The funnel 
should be about half an inch in diameter, and 5 inches 
long, and drawn at one end, tG a point about 4 mm. wide. 
Fill the point of the funnel with broken glass, up to the 
shoulder, and place upon the glass a thin layer of ignited 
asbestos, pressing it carefully against the walls of the 
funnel. Care should be taken not to make the plug of 
asbestos too thick or compact, as it is liable to become 
clogged by the carbon. The layer of asbestos should be thin 
enough to allow water to run through at the rate of a f un- 
nelful in ten seconds. Transfer the carbon to the filter, 
and wash with hot water until it is free from chlorides. 
After washing down all the carbon from the sides of the 



TOTAL CARBON. 107 

tube, cut it off about 1 inch above the layer of carbon, by 
scratching the glass with a file, and pressing a red-hot 
glass rod against the cut. Then invert the part contain- 
ing the carbon into the mouth of the decomposing flask 
of an apparatus similar to that described in the analysis of 
calcite, for the determination of carbonic acid by direct 
weight, and blow the contents into the flask, avoiding the 
use of water by wiping out any carbon that may adhere 
to the glass with a little ignited asbestos, and throwing 
this also into the flask. To the filtrate from the carbon 
add 4 or 5 c. c. of concentrated hydrochloric acid (to pre- 
vent the formation of any precipitate of basic copper salt), 
and dilute with water, until the fluid is transparent. If 
any carbon has passed through the asbestos it can readily 
be seen in the transparent fluid. Should there be any, 
allow it to settle, filter it out on another filter of ignited 
asbestos, and add it to that in the flask. Then weigh the 
absorption-tube, introduce into the flask about 3 gms. of 
chromic acid, put the apparatus together, and start the 
aspirator very slowly. After the aspirator has run long 
enough to partially exhaust the air in the apparatus, intro- 
duce, through the funnel-tube, about 30 c. c. of pure con- 
centrated sulphuric acid, close the stop-cock of the funnel- 
tube, and heat slowly up to boiling. After the acid boils, 
remove the heat, put on the guard tube, open the stop- 
cock of the funnel-tube, and aspirate slowly, until the ab- 
sorption-tube is cool. After it is thoroughly cooled, weigh 
it, and from the increase of weight, due to carbonic acid, 
calculate the carbon, (For Elliott' s description, consult A. 
Yacher's 5th Edition of Fres. Quant, Anal., London, 
1870.) (See cut on p. 25.) 

Professor Langley proposes to burn the carbon directly 
in a current of oxygen, after treating the iron with copper 
sulphate. His directions are to introduce the iron or steel 
in a finely-divided condition into the cold solution of 
copper sulphate, and raise the heat gradually, on a water- 
bath, to 80° C, with frequent stirring, and filter tbe 



108 CAST-IROTT, STEEL, ETC. 

spongy mass on a common funnel, loosely plugged with 
asbestos. A porcelain tube of about three fourths of an 
inch internal diameter is placed in a furnace, which will 
keep at least 10 inches of the tube up to a full yellow heat ; 
a plug 2 inches in length is inserted in the anterior end. 
This plug is made by coiling up fine copper bell- wire till 
it is just large enough to fill the tube closely ; the inter- 
stices between the wires will always be large enough to 
allow of the passage of gas. Air being now drawn through 
the apparatus, the copper is deeply oxidized, and thus a 
filter of oxide of copper is produced, which, at a red heat, 
will oxidize any carbonic oxide or hydrocarbon which may 
pass over it. To hold the matter to be burned, a copper 
boat is provided, which is easily made by folding up a 
piece of sheet copper ; it should be about 5 inches long, 
and, when bent, form a half cylinder with closed ends ; a 
few small holes may be made through the bottom with a 
punch, in order to make the vessel porous. On the 
bottom of the boat a stratum of asbestos is laid, and on 
this the mixed copper and carbon sponge is loosely placed. 
The anterior end of the tub§ containing the wire plug be- 
ing first heated, the boat is then introduced, and the com- 
bustion conducted in the usual manner, either in purified 
oxygen or air. (See Am. Whem., Vol. VI., September, 
1875.) 

Dr. Eggertz, of the Swedish School of Mines, has pro- 
posed a method of determining the combined carbon in 
iron and steel, by comparing the color of a solution of the 
iron or steel under examination with that of a solution of 
another sample of known constitution. When steel or 
pig-iron, containing carbon in chemical combination, is 
dissolved in nitric acid, a soluble brown coloring matter is 
formed, whose coloring power is very intense, and the 
solution assumes a tint which is dark in proportion to the 
quantity of the chemically combined carbon. Iron and 
graphite do not influence this coloration, for the solution 
of ferrous nitrate is colorless, or, at most, slightly green- 



COMBINED CARBON — COLORIMETRIC. 109 

ish, unless extremely concentrated, and graphite is insol. 
uble in nitric acid. Thus, in dissolving two pieces of dif- 
ferent steels, of the same weight, in nitric acid, taking care 
to dilute the dark solution until the two liquids present 
exactly the same color, it is very evident that the more 
highly carburetted steel will furnish the larger quantity of 
liquid, and that the proportion of the volumes will indi- 
cate the relative proportion of color in the two steels. If, 
now, the composition and per cent of carbon of one of the 
steels is known, the absolute percentage of carbon in the 
other steel may be immediately deduced. Dr. Eggertz 
has applied these reactions to a method of estimating the 
combined carbon. In a cylindrical test-tube, dissolve 
gradually in the cold 10 centigrammes of wrought-iron, 
steel, or cast-iron, reduced to a fine powder, in 1 J- to 5 c. c. 
of nitric acid of 1.2 sp. gr. The nitric must contain no 
hydrochloric acid, because the solution of iron would have 
a yellow tint. In proportion as the metal contains more 
carbon, more nitric acid must be used. After some time, 
when the chief part of the metal appears to be attacked, 
place the tube in a water-bath, and warm it to 80° C, in 
such a position that only the lower part of the tube is in 
contact with warm water ; a movement takes place in the 
acid which favors its reaction upon the metal ; a slight dis- 
engagement of gas from all the particles of carbon may be 
observed. The operation should always be conducted 
under the same conditions as to heat and length of 
time. The evolution of gas having ceased (in operating 
upon steel, the reaction must continue two or three hours), 
place the tubes in a large vessel filled with cold water, to 
bring the solution always to the same temperature. This 
precaution is indispensable, because the same liquid is 
darker when warm than when cold. Afterward, pour off, 
as exactly as possible, the clear liquid into a graduated 
burette. Upon the black residue remaining in the tube, 
pour some drops of nitric acid, and heat carefully over a 
lamp. If there is no further liberation of gas, the residue 



110 

consists of nothing but graphite or silica. Cool the new 
solution, and add it to that which is already in the bu- 
rette. The liquid is then diluted with water until its color 
corresponds exactly with that of the normal liquid, which 
latter should be of such a degree of concentration that 
each c. c. represents 0.0001 gm. of carbon. If, for instance, 
this normal liquid is prepared from cast-steel containing 
exactly 0.85 per cent of carbon, 1 decigramme of that steel 
must be dissolved in 8.5 c. c. of nitric acid; iOO gms. of 
steel, containing 85 centigrammes of carbon, would thus 
be dissolved in 8500 c. c. of the normal solution ; 100 c. c. 
of that solution would represent 1 centigramme of carbon, 
and, consequently, 1 c. c. of the normal solution would rep- 
resent 0.0001 gm. of carbon. 

To compare the normal solution with the solution of iron 
under examination, it should be contained in a tube of the 
same kind, and when the two tubes are held together by 
daylight before a thin sheet of paper, the color should be 
exactly the same in both of them. As the normal solution 
alters slightly in color by keeping, and begins to become 
paler after 24 hours, it is not possible to keep such a solu- 
tion for use in a tube hermetically sealed. A solution of 
burnt sugar in weak alcohol gives a solution of exactly the 
same shade of color as the normal solution, and maintains 
its color for a considerable time when protected from the 
light. A solution of roasted coffee in alcohol has also been 
found to be very satisfactory, But the best plan is to 
make the solution fresh, as it is required, by dissolving 0.1 
gm. of steel, containing a known amount of carbon, in 5 
c. c. of nitric acid, and diluting it to the requisite degree, 
which may be indicated by a mark upon the tube corre- 
sponding to the percentage of carbon in the steel. If an 
iron solution of exactly the same color as the normal solu- 
tion is diluted with one tenth of its bulk of water, the color 
becomes distinctly paler, so that the delicacy of the method 
may be judged of from this. 

J. Blodgett Britton, in the Jour, of tlie Franklin Insti- 



COMBINED CARBON — COLORIMETEIC. Ill 

tute for May, 1870. lias suggested a modification. 
Instead of a single tube, containing a standard solution for 
comparison, a number of tubes, having their solutions dif- 
ferently standardized one from the other, are employed. 
They are arranged securely in a wooden frame, with spaces 
between for placing the tube containing the solution to be 
tested. The tubes aTe five eighths of an inch in diameter, 
and three and a half inches in length, filled with water and 
alcohol, colored with roasted coffee, and hermetically 
sealed. The solution in the first tube has its color to cor- 
respond exactly with one produced by 1 gm. of iron con- 
taining 0.02 per cent of combined carbon, dissolved in 15 
c. c. of nitric acid. The solution in the tube next to it has 
its color to correspond with one produced by the same 
quantity of iron, but containing 0.04 per cent of combined 
carbon, and so with each of the other tubes, increasing 
0.02 per cent of carbon in regular succession, the last 
reaching 0.3 per cent, which is indicated by figures on 
the rail of the frame opposite each tube. On the back of 
the instrument is stretched some fine white parchment 
paper. 

The process is conducted as follows : 

One gm. of the finely-divided metal is put into a tube of 
about 1.5 inches in diameter and 10 inches long, and di- 
gested for 15 or 20 minutes in 10 c. c. of nitric acid of a 
little more than 1.2 sp. gr., free from chlorine. The solu- 
tion is then cautiously poured into a beaker, and a small 
portion of metal, which remains undissolved and adheres 
to the bottom of the tube, is treated with 5 c. c. of fresh 
acid, exposed to a gentle heat till completely dissolved, 
and added to the other. The contents of the beaker, when 
sufficiently cool, are filtered through two thicknesses of 
German paper (not previously moistened, and of a diam- 
meter not exceeding 4.5 inches) into a tube about five 
inches long, and of precisely the same diameter as those 
in the instrument. After the filtered solution has re- 
mained for some minutes at the temperature of the atmo- 



112 

sphere, and its color become fixed, the tube is placed in 
the instrument, and the carbon determined by a compari- 
son of shades ; the determination may be made readily as 
closely as 0.01 per cent. Heat should not be applied in 
the first instance to facilitate the solution of the metal, be- 
cause a high temperature is apt to cause a slight change 
of color. Two thicknesses of paf)er are taken be- 
cause one is liable to break, and the paper should be 
used dry, for, if previously wetted, the water will weaken 
the color of the solution, and it ought to be cut to a size 
not exceeding 4.5 inches, to prevent undue absorption. 

If the metal to be examined contains more than 0.3 per 
cent of carbon, 0.5 gm., or less, of it may be taken, or the 
solution may be diluted with an equal volume of water, or 
more, and the proper allowance made ; or an instrument 
of higher range may be used. On the other hand, if the 
metal contains a very small percentage of carbon, 2 gms. 
of it may be taken. (Compare Crookes' s Select Methods, 
p. 81.) 

For other methods, consult Fres., Quant. Anal., 4th 
London Ed., §249. 

For the determination of the graphite Eggertz's method 
is as follows : One gramme or more of iron, reduced to 
small pieces, or white pig-iron crushed in a steel mortar, 
or gray pig-iron in small chips, is dissolved in 15 c. c. of 
hydrochloric acid of 1.12 density, in a small flask covered 
with a watch-glass, and, when the iron is dissolved, the so- 
lution boiled for half an hour. All the carbon combined 
with the iron is disengaged in the form of carburetted hy- 
drogen gas, while the graphite and silica remain. If the 
carbonaceous residue, left after dissolving the iron, comes 
in contact with atmospheric air before the liquid is boiled, 
it is so altered that it is not dissolved, and disengaged as 
gas. The graphite that remains after boiling the liquid is 
collected on a filter of known weight, washed, dried, and 
weighed. It is then burnt, and the residual silica weighed 
to ascertain the weight of graphite. See Crookes' s Select 



GRAPHITIC CARBON. 113 

Methods, pp. 79 and 80, where a modification is proposed, 
as follows : 

In a beaker of 100 c. c. capacity, mix 4 c. c. of sulphuric 
acid and 20 c. c. of water, and when the heat produced by 
the combination of the water and the acid has entirely 
disappeared, shake 2 gms. of finely powdered pig-iron 
into the dilute acid, and boil for half an hour. (For steel 
and wrought-iron not less than 3 gms. should be taken, 
and the acid for solution increased in proportion. ) The 
solution is then evaporated until it measures 18 c. c, 
allowed to cool to the temperature of 50° C, and 4 c. c. of 
nitric acid of sp. gr. 1.20 added ; boil for a quarter of an 
hour, and allow to evaporate on a water-bath until, on 
holding a watch-glass over the beaker, there occurs upon 
it no perceptible condensation. To the dry mass add 30 
c. c. of water, and 5 c. c. of hydrochloric acid, sp. gr. 
1.16, boil for a quarter of an hour, and add more hydro- 
chloric acid if there appears to be anything besides silica 
and graphite undissolved. The insoluble silica and 
graphite are thrown on a filter (which has been dried at 
100° C. and carefully weighed), washed with cold water 
until the washings give no reaction for iron when tested 
with potassium ferrocyanide, then washed with boiling 
water containing 5 per cent of nitric acid. The silica and 
graphite are then dried on the filter at 100° C, and 
weighed, ignited in a porcelain crucible, and the weight 
carefully taken. The difference between the weighings 
before and after ignition gives the amount of the 
graphite. 

The objection to the method of determining the graphite 
by burning it, after drying it at 100° C, when mixed with 
silica, is that at that temperature water is not expelled 
from the silica, or even at a much higher heat. Conse- 
quently, the loss which represents the weight of graphite is 
partly water. This objection applies to all methods where 
the graphite is determined by igniting and weighing the 
residual silica. The extreme difficulty, at times, of burning 



114 

the graphite in a crucible may be considered another 
objection. 

The best method is to dissolve from 2 to 3 gms. of gray 
pig-iron, or from 4 to 5 gms. of white iron, steel, or 
wronght-iron in dilnte hydrochloric acid, and boil for 
about half an hour, filter through asbestos in a funnel 
made of glass tubing, and arranged as directed for the 
determination of total carbon ; wash with hot water until 
all acid is washed out, then with strong solution of potas- 
sium hydrate, which will remove silica, afterward with 
hot water, to wash out any potassium carbonate, of which 
the potassium hydrate is apt to contain some, then with 
alcohol (which will remove hydrocarbons) until the 
alcohol runs through the funnel colorless, again with a 
little hot water, then with ether until it passes through 
colorless, in order to displace the water, and remove 
another class of hydrocarbons, which the alcohol may have 
failed to reach. It is well, finally, to wash with a little 
hot water (particularly if the ether used is not perfectly 
pure), in order to keep the graphite from adhering to the 
walls of the funnel, when blown into the decomposing- 
flask, being careful to remove any excess of water by 
gently blowing through the funnel. After the graphite is 
thoroughly washed, it is transferred to the decomposing- 
flask, and oxidized with chromic and sulphuric acids, in 
precisely the same manner as in the determination of total 
carbon. If it is preferred, the graphite may be transferred 
to a boat, and burned in a current of oxygen as in 
" Sugar (Ultimate Analysis)." 

To determine the silicon, sulphur, and phosphorus, dis- 
solve 10 gms. of potassium chlorate in 200 c. c. of hot 
water, in a flask holding at least 1 litre, heat to boiling, 
and introduce 5 gms. of the iron, in the form of borings 
or chips. Then remove the source of heat, add (little by 
little) 60 c. c. of pure concentrated hydrochloric acid, and 
heat until the iron is dissolved, which may be known by 
there being no heavy particles on the bottom of the flask. 



PHOSPHORUS — SILICON. 115 

which will not rise when the flask is shaken. There may 
be a large quantity of black carbon in the fluid, but this 
will rise when agitated. Transfer the contents of the flask 
to a large casserole, evaporate to dryness on a water-bath, 
and then heat in an air-bath, at about 110° C, until the 
odor of hydrochloric acid cannot be detected. To the 
thoroughly dry mass add 10 c. c. of hydrochloric acid, 
and 30 c. c. of water, and heat on a water-bath until 
everything is dissolved except silica and graphite. Then 
dilute with 50 or 60 c. c. of water, filter, and wash with 
cold water, until the washings give no reaction for 
chlorine. To the filtrate add ammonia in excess, to pre- 
cipitate the ferric hydrate, which will carry the phos- 
phorus with it, and wash until the washings give no reac- 
tion for sulphuric acid. Acidulate the filtrate slightly 
with hydrochloric acid, precipitate barium sulphate as 
usual, and calculate the sulphur. In almost all cases, 2 
c. c. of a saturated solution of barium chloride will be suf- 
ficient to precipitate all the sulphur in 5 gms. of iron. It 
is well, however, to be assured that a sufficient quantity 
of the reagent has been added, by testing a few drops of 
the filtrate with sulphuric acid, as directed in the analysis 
of magnesium sulphate. 

To determine the phosphorus, dissolve the precipitate of 
ferric hydrate, containing ferric phosphate, in hydro- 
chloric acid, and proceed as directed in partial analysis of 
iron ore by Method No. 2. 

To determine the silicon, dry the residue (containing 
silica, graphite, and perhaps a little ferric oxide) left after 
filtering the solution of 5 gms. of iron, burn it in a plat- 
inum crucible, add 5 or 6 gms. of sodium carbonate, and 
2 or 3 gms. of sodium nitrate, and heat over a good burner 
until the contents of the crucible are fluid and the graphite 
oxidized. Do not heat unnecessarily. Treat the fused 
mass as directed in the analysis of feldspar for the determi- 
nation of silica. As the silica obtained may contain a 
little ferric oxide and platinum from the crucible, expel it 



116 CAST-IKON, STEEL, ETC. 

by means of hydrofluoric and sulphuric acids, and from 
the loss calculate the silicon. The estimation of the silicon 
by treating the original residue with hydrofluoric and 
sulphuric acids, before removing the graphite, would be 
erroneous, as some of the graphite would also be expelled 
by the action of the acids. Such has been the experience 
of the writer. 

A common method of determining sulphur in iron is to 
dissolve a weighed quantity of the iron with hydrochloric 
acid in a flask or retort, conducting the sulphuretted 
hydrogen formed into a solution containing some metal, 
which will be precipitated as sulphide, oxidizing the sul- 
phur of the sulphide into sulphuric acid, and precipitating 
it with barium chloride. Dr. Drown has substituted a 
solution of potassium permanganate. By his method, 5 
or 6 gms. of the iron are dissolved in hydrochloric acid, 
and the sulphuretted hydrogen resulting conducted into a 
solution of 1 gm. of potassium permanganate in 200 c. c. 
of water, contained in three tubes or bottles. After the 
evolution of the gas has entirely ceased, and air has been 
drawn through the tubes or bottles for some time, the 
contents are poured into a beaker, and the bottles rinsed 
out with water, and any manganese oxide dissolved in a 
little hydrochloric acid. Enough hydrochloric acid is then 
added to the beaker to completely decompose the per- 
manganate and convert it into a clear, colorless solution, 
in which the sulphuric acid may be directly precipitated. 
If the solution does not become perfectly clear, owing to 
impurities in the permanganate used, filtration is necessary 
before precipitation. Before precipitating the sulphuric 
acid, the residue left after treatment with hydrochloric 
acid in the flask is filtered off and washed, then evaporated 
twice to dryness with aqua regia, taken up with hydro- 
chloric acid, filtered, and the filtrate added to the main 
solution. (See Am. Chemist, Yol. IV., May, 1874.) 

For a colorimetric method of estimating sulphur in iron 
by Eggertz, see Crookes' s Select Methods, p. 85. 



CHROMIUM, ALUMINUM, ETC. 117 

For the determination of chromium, aluminum, manga- 
nese, zinc, nickel, cobalt, calcium, and magnesium, dis- 
solve 5 gms. of iron or steel, in the same manner as for the 
determination of silicon, sulphur, and phosphorus, with 
hydrochloric acid and potassium chlorate, and after 
evaporating, drying, dissolving the mass, and filtering 
out the silica (which may be determined here, as a check 
on the previous determination), proceed as directed in 
Notes 3 and 4 of " Complete Analysis of Iron Ore " for the 
determination of chromium, and the treatment of residues 
and precipitates. 

Dissolve the precipitate caused by sodium carbonate, in 
the treatment for chromium, in hydrochloric acid, add to 
it the solution of any residue, and precipitate, as directed 
in Note 4 of " Complete Analysis of Iron Ore, ' ' and boil with 
the addition of 2 or 3 c. c. of nitric acid, to ensure com- 
plete oxidation of iron. Then precipitate basic acetates 
twice, as directed in the analysis of manganese ore, filter, 
and wash well. 

In the filtrate from the basic acetates will be found the 
manganese, zinc, nickel, cobalt, calcium, and magnesium. 
For their separation and determination, consult Note 16 of 
" Complete Analysis of Iron Ore." 

If no zinc, nickel, or cobalt be present, the manganese 
may be precipitated by bromine, and determined immedi- 
ately, as directed in Note 12 of " Complete Analysis of Iron 
Ore," and the calcium and magnesium determined in the 
filtrate from the manganese as in Notes 13 and 14. 

To determine the aluminum, dry the precipitated ace- 
tates, transfer them to a silver crucible, burn the filter, add 
the ash, and fuse with pure sodium or potassium hydrate ; 
then boil the fused mass with water. By this means, the 
alumina will be dissolved. Filter, wash, acidify the 
alkaline filtrate strongly with hydrochloric acid, add 
slight excess of ammonia, and determine the alumina as 
in the analysis of potash alum, from which calculate the 
aluminum. H. Eose, who suggested the fusion with po- 



118 CAST-IRON, STEEL, ETC. 

tassium hydrate, precipitates the alumina with ammonium 
carbonate, from the solution, strongly acidified with 
hydrochloric acid. (See his Quant. Anal., " Separation of 
Alumina from Ferric Oxide.") 

To determine copper, tin, arsenic, and antimony, treat 
20 gms. of the iron in the finest possible state of division 
with a previously-heated mixture of 1 volume of nitric 
acid and 3 volumes of hydrochloric acid (both acids must 
be pure and strong) in a very capacious, long-necked, 
obliquely placed flask, at a gentle heat. When all visible 
action has ceased, decant the solution, and treat the 
residue with a fresh portion of aqua regia. Mix the solu- 
tions, dilute copiously, and treat in a large flask with 
sulphuretted hydrogen, at first in the cold, then at 70° C. 
Allow the fluid (saturated with sulphuretted hydrogen) to 
settle for 24 hours, filter, dry the precipitate, which con- 
sists principally of sulphur, and extract it with bisulphide 
of carbon. There usually remains a small black residue, 
which often contains, besides sulphide of copper, a little 
sulphide of arsenic and sulphide of antimony. (See Fres., 
Quant. Anal., § 249-5.) There may be also sulphides 
of other metals of Groups V. and VI. Filter out the 
precipitated sulphides, wash and digest the precipitate 
with potassium hydrate and potassium sulphide contain- 
ing an excess of sulphur. The copper sulphide will 
remain undissolved while the sulphides of tin, antimony, 
and arsenic will go into solution. Decompose the copper 
sulphide with nitric acid, replace the nitric with sulphuric 
acid, and determine the copper electrolyticaily, as in the 
analysis of copper ore. 

For the determination of the tin, arsenic, and antimony, 
consult analysis of type metal. 

To determine the alkaline metals, dissolve 20 gms. of the 
iron in dilute hydrochloric acid, evaporate nearly to dryness, 
on a water -bath, in order to remove large excess of free acid, 
add water, and boil. Add to the solution an excess of 
barium hydrate, and proceed as in the analysis of feldspar. 



NITROGEN. US 

To determine the nitrogen, treat about 2 gms. of the 
finely-divided cast-iron, in a tubulated retort, with a solu- 
tion of 10 gms. of neutral crystallized copper sulphate, 
and 6 gms. of fused sodium chloride. When the iron is 
dissolved, add milk of lime, and distill, until half the fluid 
has passed over into a receiver which -contains a sufficient 
amount of standard solution of sulphuric acid, and deter- 
mine the amount of sulphuric acid neutralized by the am- 
monia, which has been expelled, by titration with standard 
solution of potash, as in the analysis of guano (which 
consult; also see Fres., Quant. Anal., §249, 4th London 
Edition). For a description of the apparatus, and the 
method of making the distillation, consult Fres., Quant. 
Anal., § 99 — 3 — a., p, 157. The, ammonia is calculated to 
nitrogen. Thorpe suggests that the nitrogen, if minute in 
quantity, may be determined by Nessler' s solution. (See 
analysis of potable water.) Only a part of the nitrogen is 
evolved by this treatment ; the rest remains in the car- 
bonaceous residue. Ullgren determines this by combus- 
tion with mercuric sulphate, and measurement of the 
evolved nitrogen. The apparatus consists of an ordinary 
combustion-tube, about 30 c. c. long, one end of which is 
closed by fusion. It is then filled for about 5 c. c. with 
magnesite or sodium bicarbonate, on which is placed a 
plug of asbestos. A mixture of about 0.1 gm. of the car- 
bonaceous residue (previously dried at 130° C), and 3.5 or 
4 gms. of mercuric sulphate, is then made in an agate 
mortar, and transferred to the tube, together with a small 
quantity of mercuric sulphate, used to rinse the mortar. 
An asbestos plug follows next ; then, for about one third 
of the remainder of the tube, a layer of pumice, mixed 
with moistened mercuric sulphate and dried ; on this is 
placed a plug of asbestos. Finally, the tube is filled with 
pumice, which has been boiled in a concentrated solution 
of potassium bichromate, and allowed to drain. This serves 
to absorb the sulphur dioxide which may be formed. The 
tube is then closed with a caoutchouc stopper, through 



120 

which passes a small tube, so bent that it passes down 
into a mercury trough, and up under a vertical tube hold- 
ing about 90 c. c, having a bulb of a capacity of about 
40 c. c. blown in it, in such a way that the part above the 
bulb will hold about 20 c. c, and the part below the bulb 
about 30 c. c. The narrower part is graduated to divis- 
ions of 0.1 c. c. The tube is filled with mercury, and in- 
verted in the bath. Solution of potassium hydrate (1 part 
potassium hydrate and 2 parts water) is introduced until 
the bulb is filled to within about 10 c. c, and then 15 c. c. 
of a saturated and clear solution of tannic acid. The ex- 
treme end of the tube, where the magnesite is placed, is 
now heated gently,, the heat being gradually extended 
and increased until about half the carbonate is decom- 
posed, thus expelling the air. The turned-up end of the 
delivery-tube is then brought under the graduated-tube, 
and 'the part of the combustion-tube containing the car- 
bonaceous residue heated gently. Then the part containing 
the pumice and mercuric sulphate is heated, and when it 
is red hot, that containing the residue is heated to strong 
red heat. When gas ceases to be evolved, heat the rest of 
the carbonate to sweep the tube. Transfer the receiving- 
tube to a water-trough, when the mercury and potash will 
be replaced by water. Measure the nitrogen, making cor- 
rections for temperature and pressure, and calculate nitro- 
gen. (Fres., Quant. Anal., § 249, 4th London Edition.) 

To determine vanadium, dissolve 40 or 50 gms. of the 
iron, reduced to a finely-divided condition by filing or 
drilling, in dilute sulphuric acid. Filter out and wash the 
black residue, which will contain all but traces of the 
vanadium, and proceed as directed in Appendix 3, of 
" Complete Analysis of Iron Ore." (Consult, also, H. 
Rose, Quant. Anal., p. 498.) 

To determine molybdenum, treat a large quantity of the 
iron, as for vanadium, with dilute sulphuric acid. Filter 
out and wash the residue, digest it with yellow ammonium 
sulphide, which will dissolve the molybdenum, with other 



MOLYBDENUM — SLAG. 121 

metals whose sulphides are soluble in the alkaline sul- 
phides. Filter, wash, and acidulate the filtrate. Tore-pre- 
cipitate the sulphide, filter, wash, digest with strong nitric 
acid to oxidize the sulphur, make alkaline with ammonia, 
and filter. All molybdic acid should go into solution. 
Then make the solution sligMly acid with nitric acid, 
allow it to stand for some hours, and add solution of 
neutral mercurous nitrate in sufficient quantity. The 
yellow precipitate, which is at first bulky, soon contracts. 
Filter on a weighed filter, wash with a dilute solution of 
mercurous nitrate, dry, transfer the dry precipitate as 
completely as possible from the filter to a platinum or 
porcelain crucible, and ignite in a stream of hydrogen, 
cool, and weigh, and repeat until the weight remains con- 
stant. The heat should not be raised above gentle redness. 
Finally, weigh the dioxide, and calculate the molybdenum. 
As molybdic acid is volatile, instead of burning the filter, 
weigh it, and from the weight of the small portion of pre- 
cipitate adhering, calculate the molybdenum, and add the 
weight to the other. (See H. Rose, Quant. Anal., article 
" Molybdenum," p. 490.) 

To determine any slag that may be mixed with cast-iron, 
pulverize about 3 gms. as finely as possible by boring with a 
dull drill and rubbing in a steel mortar, being careful not 
to lose any of the dust. Add this (little at a time) to 6 
c. c. of bromine, previously mixed with 60 c. c. of water 
which has been boiled and cooled to 0° C. in a beaker of 
about 100 c. c. capacity. Keep the fluid at 0° C. for 3 
hours, with frequent stirring. No evolution of gas should 
take place. After the iron appears to have dissolved, 
allow the fluid to stand for 24 hours at the ordinary tem- 
perature of the atmosphere. Then add 30 c. c. of ice- 
water, which has been previously boiled, allow the mixture 
to settle, and decant, on a small filter, the fluid containing 
light particles of carbon. Repeat, until only hard, dark 
powder remains at the bottom of the beaker. Test this for 
mdissolved iron, by adding 2 drops of hydrochloric acid, 



122 CAST-IKON, STEEL, ETC. 

and 5 c. r. of water. If any iron be present, gas will be 
evolved. Whether iron be present- or not, decant imme- 
diately on the filter, and wash, to avoid affecting the slag. 
If the hydrochloric acid has shown the presence of iron, 
add 30 c. c. of ice-cold water, which has been previously 
boiled, and 3 c. c. of bromine, and proceed as in the first 
instance, in order to dissolve all iron. Filter, and wash 
with cold water, until the washings give no reaction for 
iron. Dry the filter and contents, ignite, transfer the 
ignited substance to a silver or platinum dish, add solution 
of pure sodium hydrate, and digest, to dissolve free 
silica. Then filter, wash well, dry, ignite, cool, and 
weigh the slag. Iodine may be used instead of bromine. 
If iodine be used, add the same quantity of iron, reduced 
to as fine a powder as possible, to 15 gms. of iodine, cov- 
vered with 15 c. c. of water, in a beaker of about 100 c. c. 
capacity, the water having been boiled previously to re- 
move any air adhering to the iodine, and cooled by stand- 
ing in ice. After adding the iron, proceed as when bro- 
mine is used. 

Consult Fres., Zeits.fur Anal. Chem., 1865, pp. 69-77 ; 
Wag., Jdhresb., 1863, p. 19 ; same, 1865, p. 27 ; same, 1868, 
p. 28 ; Comp. Bend. 2, p. 1030 ; Dingier, clxxvii., p. 388 ; 
Eggertz, Jahresb., 1863, p. 30. 



CHAPTER XVIII. 



ZINC ORE. 



Make a qualitative examination of the ore, for metals oi 
Groups Y. and VI. 

Treat 2 gms. of the finely pulverized ore, in a small 
flask, with a mixturo of 10 c. c. of hydrochloric acid, 5 
c. c. of nitric acid, and «) c. c. of sulphuric acid ; all the 
acids being pure and concentrated. Boil, until copious 
fumes of S0 3 are evolved, cool, dilute with 25 c. c. of 
water, filter, and wash well. If the qualitative analysis 
has shown the presence of oxides of the higher groups, 
add 5 c. c. of hydrochloric acid, and saturate the solution, 
which should not exceed 500 c. c, with sulphuretted hy- 
drogen. Filter, wash slightly, digest the precipitate with 
a mixture of 5 c. c. of hydrochloric acid, and 10 c. c. of 
water, over heat, dilute to about 400 c. c, and, without 
filtering, saturate with sulphuretted hydrogen. (See Fres., 
Quant. Anal., §162 — A, p. 375.) Filter, wash well with 
hot water, combine the filtrates, and boil, after adding a 
little potassium chlorate to oxidize the sulphur, and pre- 
cipitate basic acetates as usual. If no metals of the higher 
groups be present, the treatment with sulphuretted hy- 
drogen and potassium chlorate is to be omitted. In 
either case, filter out the precipitate of basic acetates, dis- 
solve it in hydrochloric acid, dilute, and precipitate again 
in the same way. Filter, dissolve the precipitate as before, 
and precipitate, a third time, with large excess of ammonia, 
filter, and wash. Combine all the filtrates, concentrate 
them to 500 c. c, acidify strongly with acetic acid, boil, 
and, while boiling, pass a rapid current of sulphuretted hy- 
drogen for half an hour. By this means, the zinc will be 
precipitated as sulphide, and the manganese be held in so- 
lution. (See Fres., Quant. Anal., § 160 — 6 — a ; also 



124 ZINC OKE. 

Gibbs, in Am. Jour. Sci. and Arts, January 7, 1868.) If 
there be a very large amount of manganese in the ore, it is 
well to dissolve the zinc sulphide in hydrochloric acid • 
make the solution slightly alkaline with sodium car- 
bonate, and then decidedly acid with acetic acid, boil, and 
treat with sulphuretted hydrogen as before, as the zinc 
may carry down some manganese with it. Filter out the 
zinc sulphide, wash it by decantation 2 or 3 times with 
hot water, and then, on the filter, with sulphuretted hy- 
drogen water, into small beakers, changing them often, in 
order not to be compelled to refilter a large amount of 
fluid, should the zinc sulphide run through the filter, 
which it is apt to do, as soon as the ammonium chloride is 
washed out. Ammonium chloride should be washed 
out, as it renders zinc carbonate soluble to a certain ex- 
tent, when the solution is afterward treated with sodium 
carbonate. Should the zinc sulphide begin to run through 
the filter, stop washing, and, into the last turbid filtrate, 
wash the precipitate from the filter as completely as pos- 
sible with water, dry the filter, moisten it with nitric acid, 
burn it, and add the ash to the precipitate. Then, add 
concentrated hydrochloric acid, and a little potassium 
chlorate, and boil until the zinc is dissolved, and the sul- 
phur oxidized. After this, dilute to 300 c. c. for each 0.500 
gms. of zinc oxide present and heat to boiling. Then, re- 
move the heat, cover the vessel, add excess of sodium car- 
bonate, and boil, to expel free carbonic acid. Wash three 
times by decantation with hot water, boiling up each 
time, and then on the filter thoroughly, and dry the pre- 
cipitate. Brush the dry precipitate as completely as pos- 
sible from the filter into a clock-glass, burn the filter in 
a weighed crucible, after moistening it with nitric acid, 
and carefully expelling the excess by heat, transfer the 
precipitate to the crucible, ignite again, cool, and weigh 
the impure zinc oxide. Should any zinc carbonate adhere 
to the vessel in which it was precipitated, dissolve it off 
into a weighed dish, evaporate to dryness, ignite, weigh. 



VOLUMETRIC METHODS. 125 

and add the weight to that of the main precipitate. Dis- 
solve the ignited precipitate in hydrochloric acid, filter 
ont any undissolved silica, wash, ignite, weigh, and de- 
duct its weight from that of the weighed precipitate. To 
the filtrate, add large excess of pure potassium hydrate, 
filter out any metallic oxides which have been precipi- 
tated by the potassium hydrate, dissolve them in hydro- 
chloric acid, and repeat the treatment. Deduct their 
weight, also. The remainder will be zinc oxide, from 
which calculate metallic zinc. 

As sodium carbonate sometimes fails to precipitate all 
the zinc, the filtrate from the zinc carbonate should be 
treated with sulphuretted hydrogen, and, if any zinc be 
recovered, its weight, after proceeding as before, should 
be added to the first. 

A great many methods, principally volumetric, have 
been proposed with the view of saving time and labor, in 
the determination of zinc. Only one, that of Fahlberg, 
published in Fres., Zeitsch., IV Hft. 1874, will be given 
here, with references to others. 

For the determination of zinc in its ores, Fahlberg dis- 
solves them with nitric and hydrochloric acids, adds an 
excess of the latter, and treats with a current of hydro- 
sulphuric acid to remove the metals of Groups V. and 
YI. After filtering, the iron is oxidized with nitric 
acid, and, when cold, precipitated with ammonium hydrate, 
+he zinc remaining in solution. If the iron should be 
found to contain zinc, it must be dissolved in hydrochloric 
acid and re-precipitated. The two filtrates are then to be 
added to each other for titration. This ammoniacal solu- 
tion is neutralized with hydrochloric acid, and further 10 to 
15 c. c. acid (sp. gr. 1.12) is added, and the titration with 
the ferrocyanide solution can then be made. The normal 
solution of potassium ferrocyanide is usually prepared so 
that 1 c. c. corresponds to 0.01 gm. of zinc, and for this 
purpose it is first titrated with a solution of pure zinc. 
The metal is first dissolved in hydrochloric acid, and to 



126 . ZINC ORE. 

the solution ammonium chloride to the extent of five 
times the weight of the metal is added, so as to obtain the 
flakes of the precipitate as fine as possible, that they may 
not, while settling to the bottom, mechanically inclose the 
potassium ferrocyanide. In this way, about 0.5 gm. zinc 
is to be prepared, and the titration performed with a 
burette provided with a good glass stopper, and divided 
into .1 c. c. At first, large flakes are obtained, but as the 
operation proceeds, they constantly grow finer. After 
each addition of the ferrocyanide, a drop is to be taken 
from the beaker and tested with solution of uranic ni- 
trate, to ascertain whether the whole of the zinc has been 
converted into ferrocyanide, and an excess of the normal 
solution added. For this purpose, a porcelain slab is used, 
which is previously moistened with a row of drops of the 
uranium solution. To these drops is added, in succes- 
sion, after each addition of the normal solution, a drop of 
the solution in course of determination ; toward the close, 
after every five drops of normal solution. As long as 
zinc remains in solution, only the white flakes of ferro- 
cyanide of zinc are seen on the slab, but on the addition of 
only a very few drops in excess of the ferrocyanide a per- 
manent brown spot is obtained. With careful manipula- 
tion the greatest possible error is 0.2 — 0.3 per cent, but 
even this could be diminished one half by the use of a 
normal solution of half strength. (See translation of 
Fahlberg's article, by Charles A. Schaeffer, Ph. D., in 
Am. Chem., Vol. Y., June, 1875.) It has been suggested 
that the accuracy of the method is increased by titrating 
the solution hot. 

For other methods, consult Fres., Quant. Anal., §248, 
4th London Edition ; also Crookes's Select Methods, p. 61 ; 
also Am. Chem., Yol. II., February, 1872. 



CHAPTER XIX. 

NICKEL ORE. 

Make a qualitative examination for metals of Groups V, 
and VI. 

Treat 5 gms. of the ore in a small flask with a mixture 
of 10 c. c. of sulphuric, 10 c. c. of nitric, and 5 c. c. of 
hydrochloric acids, all pure and concentrated, heating 
until copious fumes of sulphuric anhydride are evolved, 
adding more sulphuric acid if necessary, to avoid reducing 
the mass to dryness. Finally, cool the contents of the 
flask, dilute, filter, and wash thoroughly. 

If the qualitative examination has indicated the presence 
of metals of the higher groups, dilute the solution of 5 
gms. to 500 c. c, saturate with sulphuretted hydrogen, 
filter out any precipitated sulphides, and wash well. Add 
to the filtrate a little hydrochloric acid and potassium 
chlorate, and boil to oxidize sulphur and ferrous oxide. 

If there be no metals of the higher groups present, of 
course the treatment with sulphuretted hydrogen, and 
after oxidation with potassium chlorate, is to be omitted. 
Dilute the filtrate, after boiling, with hydrochloric acid 
and potassium chlorate if sulphuretted hydrogen has 
been used, or the first filtrate, after decomposing the ore 
with acids, if no sulphuretted hydrogen has been used, to 
1 litre, and add, with constant stirring, dilute ammonia 
until the solution is alkaline. Then filter out the precipi- 
tated ferric hydrate, and wash slightly. Dissolve the pre- 
cipitate with dilute hydrochloric acid, and precipitate 
again with dilute ammonia. Filter, wash, combine the 
filtrates, concentrated to 500 c. c, acidify slightly with 
acetic acid, boil, and saturate with sulphuretted hydro- 
gen, continuing the boiling while introducing the gas. 
Filter out, and wash the precipitated sulphides of nickel 



128 NICKEL ORE. 

and cobalt, and wash them with sulphuretted hydrogen 
water. Should any manganese oxide be present, it will be 
held in solution. To recover any possible traces of nickel 
and cobalt, add a little more acetic acid to the filtrate, 
and boil. Should any sulphide be recovered by this treat- 
ment, wash it and the main precipitate from the filter 
into a casserole, dry and burn the filters, add the ash to 
the precipitates, and dissolve all with nitro-hydrochloric 
acid. Expel excess of acid by evaporating nearly to dry- 
ness, dilute, precipitate the oxides of nickel and cobalt by 
adding to the solution an excess of pure potassium hy- 
drate, and heating for some time nearly to boiling, and 
separate the two metals by one of the following methods. 
(See Fres., Quant Anal, § 110— b— *, p. 188, and § 111.) 

The first method is due partly to Liebig and partly to 
Wohler. Wash the two oxides from the filter into a 
beaker, run through the filter, in order to dissolve what 
adheres, a saturated solution of pure potassium cyanide, 
into the beaker containing the oxides, and warm until they 
are dissolved. The solution looks reddish yellow. Heat 
to boiling to remove the free hydrocyanic acid. By this 
process the double cyanide of cobalt and potassium in the 
solution is converted, with evolution of hydrogen, into 
cobalticyanide of potassium, while the double cyanide of 
nickel and potassium in the solution remains unaltered. 
Add to the hot solution finely pulverized and elutriated 
mercuric oxide (red oxide), and boil. By this operation, 
the whole of the nickel is precipitated, partly as sesqui- 
oxide, partly as cyanide, the mercury combining with the 
liberated cyanogen. The precipitate is greenish at first, 
or, if the mercuric oxide has been added in excess, yel- 
lowish gray. Wash and ignite. The residue is oxide of 
nickel (MO). (See Fres., Quant Anal., § 100-14— b.) 

To determine the cobalt in the filtrate, Wohler directs to 
carefully neutralize it with nitric acid, and add solution 
of mercurous nitrate, as long as it produces a precipitate 
of mercury cobalticyanide. The precipitate, after 



SEPARATION OF NICKEL AND COBALT. 129 

washing and drying, is to be ignited with access of air, 
when it is weighed as black oxide of cobalt (Co 3 4 ). He 
suggests that, on account of its oxygen varying according 
to the temperature, it is better to reduce it by ignition in a 
strong current of hydrogen, and weigh the metallic cobalt. 
(See Wohler' s paper in Annal. d. CTiem. u. Pharm., LXX., 
"256, or his Mineral Analysis, p. 102. Care must be taken 
in neutralizing the filtrate before adding the mercurous 
nitrate, as the fluid must not be acid, and must not be 
strongly alkaline. The ignited oxide of nickel is very apt 
to contain some impurities ; consequently, it is better to 
transfer it from the crucible to a beaker, boil it with water, 
throw it on a filter, wash, dry, ignite, weigh again, and 
subtract the loss, probably some adhering alkali. Then 
dissolve it inaquaregia, dilute, filter, wash, dry, ignite, and 
weigh any undissolved silica, and deduct its weight also. 
Finally, add to the filtrate a large excess of ammonia, filter 
out, wash, dry, ignite, and weigh any alumina and ferric 
oxide that may be present. After deducting their weight 
from that of the original precipitate, the remainder will be 
the true weight of the oxide of nickel. From this, calcu- 
late the metallic nickel. 

Another method of separating the two metals is by 
means of potassium nitrite, recommended by H. Rose, 
and Fresenius as the best. (See Fres., Quant. Anal. § 160- 
9, p. 366). Dissolve the sulphides (obtained after precipi- 
tating the basic acetates, as directed before), in aquaregia, 
evaporate the solution nearly to dryness, and neutralize 
with potassium hydrate. Then add a concentrated solu- 
tion of potassium nitrite (previously neutralized with 
acetic acid, and filtered from any flocks of silica and alu- 
mina that may have separated) in sufficient quantity, and 
finally acetic acid, till any flocculent precipitate that may 
have formed from excess of potassa has redissolved, and 
the fluid is decidedly acid. Allow it to stand at least for 
24 hours in a warm place ; take out a portion of the super- 
natant fluid with a pipette, mix it with more nitrite, and 



130 NICKEL ORE. 

observe whether a further precipitation takes place in this 
after long standing. If no precipitate is formed, the whole 
of the cobalt has fallen down ; otherwise, the small portion 
must be returned to the principal solution, some more 
nitrate added, and, after long standing, the same test 
applied. Finally, filter and wash the precipitate thoroughly 
with an aqueous solution of neuti al potassium acetate (con- 
taining 10 per cent of the salt), displace finally the last 
portion of solution of potassium acetate adhering to the 
precipitate, by means of alcohol of 80 per cent, and dry. 
Then transfer the precipitate from the filter to a clock- 
glass, incinerate the filter in a weighed crucible, add the 
precipitate, and gently ignite all. Cool, moisten with sul- 
phuric acid, cautiously expel excess of acid, and ignite at 
low red heat. Cool and weigh the sulphate of cobalt and 
potassium (2CoSOi+3K 2 S0 4 ), and calculate the cobalt. 
One hundred parts of the residue are equivalent to 18.015 
parts CoO, or 14.17 parts Co. (See Fres., Quant. Anal. y 
§81 or Annal. d. Chem. u. Pharm., CIV., 309.) 

To determine the nickel, mix the filtrate with pure solu- 
tion of sodium or potassium hydrate in excess, heat for 
some time nearly to ebullition, decant 3 or 4 times, boiling 
up each time, filter, wash the precipitate thoroughly with 
hot water, dry, and ignite. After weighing the precipitate, 
treat it as directed in the first method, and deduct the 
weight of impurities. (Consult Fres., Quant. Anal., § 110 
p. 187.) 

Another good method of determining the nickel, and 
cobalt in ores, is to decompose them in the same manner 
as directed above, remove any metals of Groups V. and 
YI. with sulphuretted hydrogen in acid solution, filter, 
oxidize the filtrate by boiling it with hydrochloric acid 
and potassium chlorate ; dilute to about 1 litre. If no 
metals of the higher groups are present, the treatment 
with sulphuretted hydrogen, and potassium chlorate is to 
be omitted, and the original acid solution diluted to about 
1 litre. Then make the solution alkaline by adding dilute 



131 

ammonia, and stirring constantly. Filter out any precip- 
itate, dissolve it with hydrochloric acid, and precipitate 
again in the same way. Combine the nitrates, concentrate 
them to 100 c. c, add a little ammonia, transfer to a 
weighed platinum dish, and precipitate the nickel and 
cobalt together by passing a strong galvanic current, from 
a battery of 2 or 3 Bunsen elements, keeping the solution 
alkaline with ammonia. The nickel and cobalt will be 
precipitated upon the platinum in the form of a metallic 
coating. When the separation from the solution is com- 
plete, remove the dish, wash it thoroughly with hot water, 
dry and weigh it. The increase in weight expresses the 
combined weight of metallic nickel and cobalt. It remains 
to separate and determine them. Dissolve them with 
nitric acid ; determine them by either of the preceding 
methods. 

The following method of analysis of nickel and cobalt 
ores is from the pen of Fresenius, published in his Zeit. 
fur Anal. Chem., and translated by Prof. C. A. Schaeffer. 
(See Am. Chem., IV., p. 289.) 

The finely-powdered mineral or metallurgical product is 
treated with hydrochloric acid, with addition of nitric 
acid, until all soluble matter has been brought into solu- 
tion, and repeatedly evaporated, with addition of hydro- 
chloric acid, almost to dryness, in order to drive off the 
excess of nitric acid. Dilute hydrochloric acid and water 
are then added to the residue, after which it is filtered. If 
the insoluble portion is not perfectly white it is fused 
with acid potassium sulphate, the mass treated with 
hydrochloric acid and water, filtered, and the filtrate 
added to the original solution. The metals of Groups 
V. and YI. are next precipitated by hydrosulphuric 
acid. For this purpose, it is well to pass the gas through 
the solution at first at about 70° C, and afterward in the 
cold. The filtered solution is then warmed, and the iron 
©sddized with nitric acid ; ammonia in excess in then added, 
and the impure ferric hydrate filtered off. After washing* 



132 NICKEL ORE. 

this is dissolved in hydrochloric acid, the solution largely 
diluted, and, after addition of ammonium chloride, a di- 
lute solution of ammonium carbonate is added, in the 
cold, until a point is reached where the liquid becomes 
cloudy, but no precipitate is visible. On standing, the 
liquid should not again become clear, but rather more 
cloudy, although the reaction at this point must be defi- 
nitely acid. It is next heated to boiling, the precipitate 
of basic oxide of iron is washed, first by decantation and 
afterward on the filter with boiling water ; a portion of 
the precipitate is ithen examined for nickel by dissolving 
it in hydrochloric acid, repeating the precipitation as 
basic oxide, and testing the filtrate with ammonium sul- 
phide, in order to see whether it is perfectly free from that 
metal. If, in this operation, a small amount of nickel 
should still be found, the whole precipitate must be dis- 
solved in hydrochloric acid, and the iron again separated 
as basic oxide, as above. The two, or, as the case may be, 
three filtrates which contain nickel and cobalt are next 
acidulated with acetic acid, and concentrated by evapora- 
tion. If, by this means, a trifling precipitation of ferric 
or aluminic hydrate take place, the precipitate must be 
filtered off, dissolved in hydrochloric acid, and again 
separated with ammonia in excess, and this operation re- 
peated once more. The filtered solution, containing all 
the nickel and cobalt, having been sufficiently concen- 
trated, is treated with sodium carbonate until the reaction 
is decidedly alkaline, acetic acid is then added to acid re- 
action, and, to the clear liquid (30-50 c. c. ), a solution of 
sodium acetate (1 : 10) is added. Hydrosulphuric acid is 
then passed through the solution, warmed to about 70° C, 
until the latter is saturated with that gas. The separation 
being completed, the precipitate of the sulphides of nickel 
and cobalt is filtered, washed, and dried. The filtrate is 
concentrated by evaporation ; hydrosulphuric acid, am- 
monium sulphide, and acetic acid are added to it, and 
thus frequently a little more of the sulphides of nickel and 



ERESENIUS'S METHOD. ' 133 

cobalt is obtained. It is well to test the nitrate in this 
way once again, in order to be quite sure that the whole of 
the nickel and cobalt has been obtained as sulphides. 
The dried sulphides of nickel and cobalt, together with 
the filter ash, are now treated with hydrochloric acid, 
with addition of nitric acid, until all has been dissolved, 
the solution evaporated with addition of hydrochloric 
acid in order to drive off the nitric acid, diluted with 
water, filtered, and the nickel and cobalt precipitated with 
pure potassium hydrate in a large platinum dish. The 
precipitate obtained must be very thoroughly washed by 
decantation afterward on the filter, with boiling water, 
dried, incinerated and heated to bright redness in a Rose 
crucible, in a current of pure hydrogen, until the weight re- 
mains constant. The metallic nickel and cobalt are next 
treated in the crucible with boiling water. Should this 
show an alkaline reaction or the presence of chlorine or 
sulphuric acid, or yield a residue when evaporated on 
platinum foil, the metals must be exhausted with boiling 
water, heated in a current of hydrogen, and again 
weighed. The metals are now dissolved in hydrochloric 
acid, after which a small amount of silicic acid usually re- 
mains. This is to be collected on a filter, burned, and 
weighed. The hydrochloric acid solution is nearly neu- 
tralized with ammonia ; ammonium carbonate is added in 
excess, and the liquid slightly warmed for some time. A 
trifling precipitate of ferric and aluminic hydrates, which 
in most cases is obtained, is filtered, dissolved in hydro- 
chloric acid, again precipitated, and ignited, first in the air 
and then in a current of hydrogen. Its weight, together 
with that of the silicic acid, is then to be subtracted from 
the original weight of the metals. As can easily be seen, 
it will in most cases be allowable, and a great saving of 
time, to incinerate the little filter containing the silicic 
acid, and that containing the ferric and aluminic hydrates 
in the same small crucible, and then, after treatment with 
hydrogen, to weigh all these impurities together. Should, 



134 NICKEL ORE. 

however, the ash of these, in consequence of the presence 
of a small amount of cobalt, appear bluish, it must be 
fused with an alkaline carbonate, and the silicic acid, etc., 
thus obtained be perfectly pure. 

If the ore or metallurgical product contain zinc, the 
nickel and cobalt obtained by the above method would be 
contaminated with that metal, since zinc cannot be entirely 
removed either by the precipitation of the hydrates with 
excess of potassium hydrate, or by the reduction of the 
oxides in a current of hydrogen. In this case, the hydro- 
chloric acid solution of the metals precipitated by ammo- 
nium sulphide is evaporated to a small volume ; and pure, 
finely-crystallized ammonium chloride is added to it in 
such quantity that, for 0.2 gm. oxide of zinc, there shall be 
about 5 gms. ammonium chloride. It is then evaporated 
to dryness on a water-bath, and carefully heated, until all 
the ammonium chloride, and with it all the zinc, is driven 
off. The residue, which consists of metallic nickel and 
cobalt, is dissolved in hydrochloric acid, with the addition 
of nitric acid, the greater part of the excess of free acid 
driven off, and the oxides precipitated with potassium 
hydrate, and further treated exactly according to the 
above method. 

If nickel and cobalt are to be determined separately, 
the ammoniacal filtrates, obtained after separation of the 
contaminating substances, are evaporated to dryness, the 
ammonium compounds are driven off by gentle heat, the 
residue dissolved in hydrochloric acid, with addition of 
nitric acid, and if much nickel and little cobalt are present, 
the latter is separated by means of potassium nitrite. If, 
on the contrary, much cobalt and little nickel are present, 
it is found more advisable to add, to the solution of the 
chlorides, potassium cyanide in excess, and to precipitate 
the nickel as the black hydrate oxide of nickel, by warm- 
ing with bromide after the addition of the potassium 
hydrate. In the first case, the potassio-cobaltic nitrite, 
and in the second, the hydrated oxide of nickel, is dis- 



IMPURITIES IJST PRECIPITATES. 135 

solved in hydrochloric acid, precipitated with potassium 
hydrate, and determined in the metallic condition. In 
these determinations, the weighings must be followed by 
an examination for silicic acid, and impurities insoluble in 
ammonium carbonate. 



Note. — For the determination of nickel and cobalt by the battery see Luckow, 
Fres., Zeitschrift fur Anal. Chem., XIX., p. 1., orDingler's Polyt,, vols. CLXXVII 
and CLXVIII. Organic salts, as acetates, etc., aid this precipitation (Luckow). 
Ammonium chloride in the solution interferes with this separation according to 
Luckow (Fres., Zeitschrift, XL, 11), Wrightson (ibid, XV., 297), Schroeder (ibid, 
XVI., 344), Beilstein (Berichte Dent. Chem. Oesell, XI., 1715), Riche (Comptes 
Bend., LXXXV., 326) and others. 



CHAPTER XX. 

COPPER ORE. 

For directions for making a complete analysis of cop- 
per ore, consult Fres., Quant. Anal., § 242. It is pro- 
posed here to give directions for the separation and de- 
termination of copper alone. 

The first step is to make a careful qualitative examina- 
tion of the ore. Then introduce 1 gm. of finely-pulverized 
ore into a flask holding about 200 c. c. , add 5 c. c nitric, 
2 c. c. hydrochloric, and 10 c. c. sulphuric acid (the acids 
should all be pure and poncentrated), boil until all the 
nitric acid is expelled, and dense white fumes of S0 3 are 
evolved. The nask should be filled with them. Then 
cool, dilute with about 50 c. c. of water, filter, and wash 
with about 75 c. c. more. Digest the residue with nitric 
and hydrochloric acids, and if the solution gives any 
reaction for copper, add sulphuric acid and treat as before. 
Treat a third time, if necessary. 

If the ore be very poor, more than 1 gm. should be 
taken, and treated with a corresponding amount of the 
three acids. 

Should no metals of Group VI. or any of Group V. 
besides copper be present, dilute the solution to 200 c. c. , 
or if it already exceeds that volume, concentrate to 200 
c. c, and divide into two exactly even parts. Introduce 
each into a weighed platinum dish, and precipitate the 
copper by a galvanic current, the dishes being connected 
with the zinc or negative pole of a battery (consisting of at 
least two Bunsen elements) by resting on a coil of the wire 
or a copper disk to which the wire is soldered, while the 
fluid in the dishes is connected with the positive pole 
by a wire attached to platinum foils which hang in 
the fluid. When the copper is entirely precipitated 
(which can be determined by testing a few drops of the 



ELECTROLYTIC DETERMINATION. 137 

fluid with sulphuretted hydrogen water), pour out the 
contents of the dishes into a beaker, wash them (two or 
three times) with hot water in+o the same beaker, and then 
with alcohol, to displace the water, decanting the alcohol 
off, as completely as possible, into another vessel. Then 
dry the dishes over a low flame until the small quantity 
of alcohol adhering to the copper is expelled, and weigh 
them. The increase in weight represents the weight of 
metallic copper. The difference in weight of copper in the 
two dishes should not exceed one tenth of one per cent. 
Should it do so, another determination must be made. 

In evaporating off the alcohol, the dishes should not be 
allowed to become so hot that they cannot be carried to 
the balance on the naked hand, and be cool enough to 
weigh in five minutes. It is unnecessary to place them in 
a desiccator. i 

The copper should be bright red in color, free from 
all dark spots, and so firmly attached to the dish as not to 
be washed off by water. The formation of spongy copper 
is an indication that too much ore has been used for the 
capacity of the dish, or that the current has been too 
intense. 

This is the best method in most cases. 

To prove the accuracy of this method, Mohr mixed 1 
gm. of pure metallic copper with 0.5 gm. of gold, silver, 
platinum, tin, lead, iron, zinc, nickel, cobalt, bismuth 
arsenic, uranium, mercury, molybdenum, antimony, sul- 
phur, silica, and calcium phosphate, treated the mixture in 
a similar manner, precipitating the_ copper in a platinum 
dish with metallic zinc instead of the galvanic current, and 
recovered 0.996 gm. of copper. In more than 20 determi- 
nations of copper in various combinations, the average 
amount of the metal obtained by this method was 99.7 per 
cent of the actual quantity present. 

If arsenic or antimony be present in the ore, it is safer 
to remove them by saturating the solution with sulphu- 
retted hydrogen, making it alkaline with potassium 



138 COPPEE ORE. 

hydrate, and warming gently for some time to dissolve 
the sulphides of arsenic and antimony. Filter and wash 
the copper sulphide, which may contain some other sul- 
phides of metals of Group V. If it does not contain them, 
or only lead sulphide, dissolve in nitric acid, add sul- 
phuric acid, evaporate to dense fumes of S0 3 , cool, dilute, 
filter out any insoluble residue, and proceed to determine 
the copper electrolytically, as directed above. When 
other metals of Group V. are present, treat the sulphides 
with pure potassium cyanide, which will dissolve the cop- 
per sulphide, and leave the others undissolved. Then 
treat the solution with nitric acid, boil to expel hydro- 
cyanic acid, add sulphuric acid, heat to expel nitric acid, 
and proceed as before. 

Determination as cuprous sulphide (Cu 2 S) : 

Instead of dissolving the copper sulphide in nitric acid, 
and evaporating the solution after addition of sulphuric 
acid, dry it, transfer the precipitate to a watch-glass, burn 
the filter in a weighed porcelain crucible provided with a 
perforated cover (known as Rose's crucible), add the pre- 
cipitate and some pure powdered sulphur, and burn in a 
current of hydrogen, over a blast-lamp. Weigh as Cu 2 S. 
(Compare H. Rose's Quant. Anal., pp. 105 and 255, chap- 
ter on copper ; also, Fres., Quant. Anal., § 119-3, p. 230, 
and Jour.f. PraM. Chem., CVIL, 110, andLXIL, 252. The 
results are very accurate. The method is the best one, 
where the electrolytic method cannot be conveniently 
applied. 

Determination as oxide : 

Decompose the ore as directed in the first instance, and, 
after separating the copper from other associated metals, 
as directed above, add to the solution, after evaporating 
off excess of acid, and heating to boiling, dilute solution 
of pure potassium or sodium hydrate, in excess, and con- 
tinue to boil until the cupric hydrate, which is pale blue, 
is converted into brownish black cupric oxide. Allow the 
precipitate to settle, filter, wash by decantation with boil- 



DETERMINATION AS OXIDE. 139 

ing water several times, transfer to the filter, wash well 
with boiling water, dry, ignite intensely, and weigh. Then 
add a few drops of nitric acid, evaporate off excess of acid, 
ignite cautiously, cool, and weigh. From the weighed 
cupric oxide calculate metallic copper. 

The action of reducing gases must be carefully avoided. 
The addition of nitric acid, and second ignition is to over- 
come any difficulty arising from this cause. Consult 
Fres., Quant. Anal., § 119 — 1 — a., for precautions to be 
observed and difficulties to be encountered. 

There are various volumetric methods of determining 
copper, for some of which consult Fres., Quant. Anal., 
§ 119, p. 225. 



CHAPTER XXI. 

GERMAN SILVER. 

The metals to be looked for usually are copper, nickel, 
zinc, and iron, which last is sometimes added to make 
the metal white. Lead is sometimes found in small 
quantity. 

Introduce 0.500 gm. of the alloy into a 200 c. c. flask, 
add 5 c. c. of concentrated nitric acid, and 15 c. c. of water, 
and heat until the alloy is dissolved. Then cool, add 10 
c. c. of concentrated sulphuric acid, and heat until dense 
fumes of S0 3 are evolved. Cool, dilute to 50 c. c, 
and filter out lead sulphate, if necessary. Divide the 
filtrate into 2 equal parts, and determine the copper in each 
electrolytically, as directed in the analysis of copper ore. 
Combine the solutions (after precipitating the copper) to- 
gether with the washings (after boiling out the alcohol 
from them), add sodium carbonate until the fluid is slightly 
alkaline, and then acetic acid until it is acid, and precipi- 
tate basic ferric acetate as usual. Dissolve the precipitate 
in hydrochloric acid, re-precipitate the ferric hydrate by 
amnionic hydrate, filter, dry, ignite, and weigh, and calcu- 
late it to metallic iron. 

To the filtrate, add pure potassium hydrate in large ex- 
cess. Nearly all the zinc will be held in solution, while 
the nickel, with, perhaps, a little zinc, will be precipitated. 
Allow the precipitate to settle, decant the clear fluid into 
another vessel, and add to the precipitate a concentrated 
and filtered solution of pure potassium cyanide, and digest 
over heat, until the precipitate goes into solution. It 
sometimes happens that a portion of it resists the action 
of the cyanide. When such is the case, filter it out, and 
as it contains no zinc, dissolve it in hydrochloric acid and 
potassium chlorate, and reserve it to be added to the solu- 



ZINC — NICKEL — IRON. 141 

tion containing the nickel after precipitating the zinc. 
Combine the other solutions containing zinc and nickel, 
neutralize with hydrochloric acid, leaving the fluid only 
slightly alkaline, add potassium sulphide until all the zinc 
is precipitated, filter, and determine the zinc as directed in 
analysis of zinc ore. 

Add to the filtrate from the zinc sulphide, the solution 
of the small portion which resisted the action of potas- 
sium cyanide, add more hydrochloric acid, if necessary, 
and boil, to decompose the cyanides, and expel cyanogen. 
Then make the solution strongly alkaline with ammonia, 
filter out any ferric hydrate, calculate it to metallic iron, 
and add the per cent to that obtained from the acetate. 
In the ammoniacal filtrate from the ferric hydrate, deter- 
mine the nickel electrolytically, as in the analysis of 
nickel ore. 

As the above operations may introduce such amounts 
of salts as to interfere with concentration for the battery 
precipitation, it may be preferable to precipitate out the 
nickel and redissolve. In such a case add ammonium 
sulphide — stir it in well — render just acid with acetic 
acid, and allow the solution to stand for some time. Then 
decant through a filter, allowing as little of the precipitate 
as possible to get upon the filter ; dissolve the precipitate 
in hot nitric acid, destroy the carbon of the filter by fusing 
with a small amount of alkaline nitrate, and add to the 
solution of the precipitate. The neutralization by ammo- 
nia, etc., may then be conducted as usual. 

If the analysis be made entirely without the use of a bat- 
tery, after dissolving the alloy, and removing any lead as 
above, precipitate the copper as sulphide, ignite it, after 
adding sulphur, in a current of hydrogen, and weigh the 
ignited precipitate as cupreous sulphide. (See analysis of 
copper ore.) 

Boil the filtrate from the copper sulphide, with potas- 
sium chlorate, and determine the zinc, nickel, and iron as 
above. 



CHAPTER XXII. 



GALENA. 



Treat 1 gm. with fuming nitric acid, and sulphuric acid. 
Note 1. 



Residue (a). 
Lead sulphate and gangue. Note 2. 



Residue (5). 
Lead carbonate 
and gangue. Note 
2. 



Solution (b). 
Alkaline sulphate 
reserve. Treat 
withH 2 S. Note 2 



Filtrate (a). 
Silver and other metals. 



Note 4. 



Filtrate (e). 
Iron, zinc, cop- 
per, etc. Note 4. 



Precipitate (e). 
Silver. Note 4. 



Solution (c). 
Lead acetate. Note 3. 

Precipitate (d). 
Lead sulphide. Note 3. 



Residue (c). 
Insoluble gangue. Note 2. 



Filtrate (d). 
To be combined with solution (5> 
residue (c), and filtrate (e). Notes 
1 3 and 4. 

Notel. — Introduce into a flask holding about 200 c. c, 1 
gm. of finely pulverized galena, previously dried at 100° 
C.j add 4 or 5 c. c. of red fuming nitric acid, and cover 
with a watch-glass. After the violent action is over, heat 
on a water-bath for some time, to oxidize the sulphur. 
After the sulphur is oxidized, add 3 or 4 c. c. of sulphuric 
acid previously diluted with 3 or 4 c. c. of water, and heat 
over a burner until the nitric acid is expelled, and dense 
white fumes of S0 3 appear. Then cool, dilute cautiously 
with about 50 c. c. of water, filter, and wash the residue 
containing lead sulphate and gangue, with about 100 c. c. 
of water containing 1 per cent of sulphuric acid, and then 
with 30 or 40 c. c. of alcohol. 

There will be a residue (a) on the filter containing lead 
sulphate and gangue, and a filtrate (a), containing silver, 
and other metals. 

Note 2. — Wash residue (a) into a beaker, add about 50 
c. c. of strong solution of ammonium carbonate, and digest 



LEAD — SILVER. 143 

on a water-bath, with frequent stirring for 10 or 12 hours, 
to convert the lead sulphate into carbonate. Filter, and 
wash well with a solution of ammonium carbonate, and 
then with hot water to dissolve out all alkaline sulphate. 

There will be a residue (b) of lead carbonate and gangue, 
and a, filtrate (b) of alkaline sulphate. Dissolve the lead 
carbonate through the filter with hot acetic acid, keeping it 
covered until effervescence ceases, and is not renewed upon 
the further addition of acetic acid. Wash thoroughly, to 
remove all lead acetate from the gangue remaining on the 
filter. Treat filtrate (b) with H a S, and add precipitate to 
precipitate (d). 

There will be a solution (c) of lead acetate and a residue 
(c) of insoluble siliceous gangue. 

Note 3. — Saturate solution (c) with sulphuretted hydro- 
gen, filter, and wash with hot water. There will be a pre- 
cipitate (d) of lead sulphide, and a filtrate (d) which is to 
be combined with solution (5), residue (c), and filtrate (e). 
Wash the lead sulphide, or precipitate (d\ into a cas- 
serole, dry the filter, burn it in a porcelain crucible, cftor 
moistening it with a few drops of nitric acid, treat the ash 
with a little dilute nitric acid, and, when it is dissolved, 
wash the solution into the same casserole, add 3 or 4 c. c. 
of sulphuric acid, and heat until fumes of S0 3 appear. 
Then cool, dilute with 30 or 40 c. c. of water, filter, wash 
with about 50 c. c. of water containing 1 per cent of sul- 
phuric acid, and finally with about the same quantity of 
alcohol. Dry the filter and contents at a moderate heat 
(not over 100° C), and, when dry, brush the contents 
into a glass as completely as possible, burn the filter in the 
way directed above, in a weighed porcelain crucible, add 
to the ash 5 or 6 drops of nitric acid and 2 or 3 drops of sul- 
phuric acid, evaporate the excess of acid, add the precipi- 
tate, and ignite all. Cool and weigh the lead sulphate, 
and calculate the lead. 

Note 4. — To filtrate (a), containing the silver, add, after 
boiling out the alcohol, about 1 c. c. of hydrochloric acid. 



J44 GALENA. 

Should any turbidity of the fluid be occasioned by the 
hydrochloric acid, let the solution stand for some hours in 
a warm place, until the precipitate settles, filter, and wash. 

There will be a precipitate (e) of silver chloride, and a 
filtrate (e), containing other metals. 

Dry the precipitate, remove it, if possible, from the filter, 
burn the latter in a weighed porcelain crucible, add to the 
ash a few drops of nitric acid and hydrochloric acid, 
evaporate to dryness, add the precipitate, and fuse at a 
low red heat. (See analysis of barium chloride. ) From 
the weight of silver chloride, calculate the silver. 

To filtrate (e\ after adding solution (&), residue (c), and 
filtrate (d\ add excess of sodium carbonate, and a little 
sodium nitrate, evaporate to dryness in a platinum dish, 
fuse, and determine the other constituents of the ore. 

Note 5. — It is better to determine the sulphur in a sepa- 
rate portion. For this purpose, heat 1 gm. of the finely 
pulverized galena in a large porcelain crucible, at 100° C, 
with a strong solution of potassium hydrate, for an hour, 
and pass a slow current of chlorine through the fluid. The 
sulphur will be converted into sulphuric acid. Then filter, 
wash, acidify the filtrate with hydrochloric acid, and pre- 
cipitate the sulphur as barium sulphate, as usual. Bro- 
mine may be used to oxidize the sulphur, instead of chlor- 
ine. (See Jour. f. PraM. Chem., LXL, 134, and Compt. 
Rend., 37, 835.) 

Note 6. — If it be desired to determine a small quantity 
of silver in the presence of a large quantity of lead, by a 
wet method, consult Fresenius's Analysis of Refined Lead, 
mZeits. fur Anal. Chem., Yol. VIII. , 1869. 



Note. — The ammonium carbonate used in Note 2 should be a solution of the 
solid salt made without addition of ammonium hydrate. A more rapid method 
consists in using a solution of ammonium citrate with ammonia, which will at once 
dissolve the lead sulphate. From this solution, neutralized by sulphuric acid, the 
lead may be precipitated by H a S, and the precipitate converted into sulphate by 
oxidation with nitric acid, and subsequent treatment with sulphuric acid. 



CHAPTER XXIII. 

TIN ORE. 

There are many methods proposed for the determination 
of tin in ores. Probably, the fnsion of the ore with sul- 
phur and sodium carbonate is, as Rose remarks, p. 392, 
the best. It requires, however, the exercise of great care 
and judgment to make it successful. It is as follows : 

Fuse 1 gm. of rich ore, very finely pulverized, with 3 
parts of sulphur, and 3 parts of dry sodium carbonate 
(after mixing the ore and flux thoroughly), in a large 
porcelain crucible, for about one hour, over a Bunsen 
burner. The heat should not be too great, or continued 
too long, as, under such circumstances, the sulphide of tin 
may be oxidized and become insoluble when the fused 
mass is treated with water. By the fusion, sulphides of 
tin and sodium are produced, and, upon adding water, the 
tin sulphide should go into solution in the sodium 
sulphide, as sodium sulpho-stannate, and will — if the fusion 
has been properly conducted. After fusing as directed, 
cool, place the crucible in a casserole, add hot water, and 
digest on a water-bath until the fused mass is disinte- 
grated and removed from the crucible. Then filter, wash 
thoroughly with hot water, and acidulate with sulphuric 
acid, to precipitate the tin sulphide. Allow the sulphide 
to settle completely, in a warm place, pour the clear fluid 
on a filter, wash 4 or 5 times by decantation, and then 
moderately on the filter with hot water. Should the pre- 
cipitate show an inclination to run through the filter, 
wash with solution of ammonium acetate (Bunsen). Put 
the filter, with the not yet quite dry precipitate on it, into a 
weighed porcelain crucible, and apply a very gentle heat, 
with free access of air, until the odor of sulphurous acid is 
no longer perceptible. Increase the heat now gradually, to 



146 TIN ORE. 

a high, degree of intensity, and treat the residue repeat- 
edly with some carbonate of ammonia, in order to insure 
the complete expulsion of the sulphuric acid which may 
be present. Were you to apply a very intense heat from 
the beginning, fumes of stannic sulphide would escape, 
which burn to binoxide (H. Rose, p. 393). The residue 
left after the first fusion and solution, should be fused 
again, and treated in the same way ; and even a third and 
fourth time, or until no more tin can be recovered. 

After weighing the stannic oxide, it shou]d be examined 
for silica. To do this, weigh out a portion, and fuse it 
with 3 or 4 parts of a mixture of equal weights of sodium 
and potassium carbonates, boil with water, filter, wash, 
acidulate the filtrate with hydrochloric acid, and should 
silica separate, filter, and reserve the filter and con- 
tents. Then precipitate the tin with sulphuretted hydro- 
gen, filter out the sulphide, and treat the filtrate as usual 
for silica, finally filtering through the reserved filter, 
already containing some silica. Calculate the silica thus 
found, to the whole amount of stannic oxide, and, after 
deducting it, calculate the metallic tin. 

Examine the residue left (after fusing, and filtering out 
the solution of alkaline stannate as directed above) for 
iron, by dissolving it in hydrochloric acid and a few drops 
of nitric acid, and precipitating the ferric hydrate with 
excess of ammonia. Should any be found, it must be 
calculated to the whole amount of stannic oxide first 
weighed, and deducted from it, as was the silica. It must 
be calculated also to metallic iron, and the per cent added 
to that found elsewhere. 



CHAPTER XXIV. 

BRONZE. 

The metals to be looked for are copper, tin, lead, zinc, 
and iron. 

Dissolve 1 gm. of the alloy, in a small covered beaker, 
in a mixture of 2 c. c. of nitric acid, 8 c. c. of hydro- 
chloric acid, and 10 c. c. of water, dilute to 200 c. c, heat 
gently, add crystals of sodium carbonate until a distinct 
precipitate forms, and boil until the basic carbonate of 
copper turns black. Then cool, add nitric acid, drop by 
drop, until the reaction is distinctly acid, and digest for 
several hours at a gentle heat until the stannic oxide is 
white. Then filter it out, wash, dry, ignite strongly, and 
weigh it. The stannic oxide must then be examined for 
silica and iron (as directed in the analysis of tin ore), 
which are to be deducted before calculating the tin. (See 
Fres., Quant Anal., § 164— B— 4— a, p. 391.) 

The ignited stannic oxide may be purified, by first treat- 
ing it with sulphuric acid and ammonium fluoride (the 
silica being determined by loss), and then fusing it with 
the two carbonates, as in analysis of tin ore, dissolv- 
ing and filtering out the stannate, and in the residue deter- 
mining the ferric oxide, to be deducted from the stannic 
oxide, and also calculated to metallic iron, the per cent of 
which is to be added to that found elsewhere. 

Evaporate the filtrate from the stannic oxide, after 
adding about 10 c. c. of sulphuric acid, until fumes of SO s 
are evolved, dilute, filter out lead sulphate, and calculate 
lead. (See analysis of galena.) 

After filtering out the lead sulphate, and washing, deter- 
mine the copper in the filtrate electrolytically. (See 
analysis of copper ore.) 

In the residual fluid, after extracting the copper, precip- 



148 BRONZE. 

itate the zinc by sodium carbonate, and proceed as directed 
in the analysis of zinc ore. Dissolve the weighed zinc 
oxide in hydrochloric acid, filter out and determine any 
residual silica, and deduct its weight from that of the 
oxide. Then add to the filtrate, excess of pure potassium 
hydrate ; filter out and wash the ferric hydrate, dissolve it 
in hydrochloric acid, and precipitate again with potassium 
hydrate, filter, wash, dry, ignite, and weigh the ferric 
oxide, which is also to be deducted from the first weight 
of zinc oxide. The remainder, after deducting the weight 
of silica, and that of ferric oxide, is to be calculated to 
zinc. 

Combine the weight of ferric oxide found here, with that 
found in the purification of the stannic oxide, and calcu- 
late to metallic iron. 

The analysis may be made in another way. Determine 
the tin and lead, as above, in the filtrate, precipitate the 
copper as sulphide, and determine it as cupreous sulphide. 
(See analysis of copper ore.) Then oxidize the sulphur 
in the solution, by boiling with potassium chlorate, and 
determine the zinc and iron as above. 



CHAPTER XXV. 

ARSENIC ORE. 

Introduce 1 gm. of the finely pulverized ore, into a large, 
covered porcelain crucible, add 15 c. c. of strong nitric- 
acid, and evaporate to pasty condition ; then add 3 or 4 
gms. of dry sodium carbonate, and as much sodium nitrate ; 
heat cautiously to perfect dryness, and fuse until the con- 
tents of the crucible are fluid. Then cool, place the cru- 
cible and contents in a casserole, containing about 200 c. c. 
of water, and heat until the mass is disintegrated so far as 
to leave the crucible. Then remove the crucible, wash it, 
adding the washings to the fluid in the casserole, boil until 
the mass in the casserole becomes pulverulent, and the 
fluid concentrated to 150 c. c. Cool, add 50 c. c. of alcohol 
stir well, filter, wash with 40 or 50 c. c. of dilute alcohol, 
(containing 1 volume of alcohol, and 2 volumes of water). 
It is advisable to dry the residue, and repeat the fusion 
and other treatment, described above. Combine the solu- 
tions which will contain the arsenic, in the form of sodium 
arsenate, and also, perhaps, a little silica and alumina. 
Boil out the alcohol, keeping up the volume of fluid by 
occasionally adding water, and, after removing the 
alcohol, acidulate with nitric acid ; add, 50 c. c. of the 
ordinary solution of ammonium molybdate, and warm for 
several hours, to precipitate the arsenio-molybdate. After 
the precipitate has entirely settled, filter, and wash with 
the precipitant ; dilute with an equal volume of water, as 
in the determination of phosphoric acid. Dissolve the 
precipitate through the filter with dilute ammonia, wash 
the filter well with the same, and allow the solution tc 
stand 12 hours, when any silico-molybdate present will be 
decomposed, and the silica separate. Filter out the raili ca 
wash with water, and acidify the filtrate with nitric ac id 



150 ARSENIC ORE. 

The arsenio-molybdate will be precipitated, and the 
alumina remain in solution. Filter, wash with 30 or 40 
c. c. of diluted ammonium molybdate solution, dissolve 
through the filter with ammonia diluted with an equal 
volume of water, wash with the same, and, to the filtrate, 
add 4 or 5 c. c. of " magnesium mixture," and allow it to 
stand for 12 hours. After the precipitate has settled, test 
as to whether or not a sufficient amount of the precipitant 
has been used, by mixing a few drops of the clear fluid 
with a little sodium phosphate. If no precipitate appear, 
which is very improbable, add more u magnesium mix- 
ture," and allow the whole to stand until the magnesium 
arsenate has had time to form and settle completely ; 
then filter, and wash with dilute ammonia, containing one 
third its volume of alcohol. Dissolve the precipitate 
through the filter into a small beaker with dilute hydro- 
chloric acid, add slight excess of ammonia, and alcohol to 
the amount of one third the volume of the solution, and 
allow all. to stand for several hours. Then filter, wash 
with dilute ammonia containing alcohol, dissolve the moist 
precipitate through the filter with dilute nitric acid, into a 
small porcelain dish, or large porcelain crucible, previously 
weighed ; evaporate to dryness, ignite gently at first, and 
then strongly, over a good Bunsen burner, and weigh the 
magnesium pyro-arsenate. (See Jour. London Chem. Soc, 
August, 1877, p. 222; taken from Zeit. f % Anal. Chem., 
XIV., 356.) The results are accurate. By the ordinary 
method of drying the precipitate of magnesium arsenate, 
on a weighed filter at 100° or 105° C, not only water is ex- 
pelled, but also ammonia. (See a paper by Maclvor, in 
Chem. JVews, Dec. 17, 1875.) The author's experience 
confirms Maclvor' s conclusion. 

After weighing the magnesium pyro-arsenate, in order 
to test it for phosphoric acid, dissolve it in hydrochloric 
acid, add sodium sulphite, saturate with sulphuretted 
hydrogen, filter out the arsenious sulphide, wash well, add 
to the filtrate large excess of nitric acid, boil down to small 



ARSENIC. 151 

volume (repeating the addition of nitric acid and boiling, 
if necessary), until the sulphur is all oxidized, and hydro- 
chloric acid expelled. Then add 10 or 15 c. c. of am- 
monium molybdate solution. Should a precipitate of 
phospho-molybdate occur, determine the corresponding 
magnesium pyro-phosphate, and deduct it from the mag- 
nesium pyro-arsenate weighed before, and calculate the 
arsenic. 

Where absolute accuracy is not required, the analysis 
may be made more expeditiously by treating the ore with 
strong nitric acid, adding sodium carbonate and sodium 
nitrate, evaporating, and fusing in a platinum crucible, 
removing the heat as soon as the flux is fluid, and then di- 
gesting with hot water until the mass is pulverulent. By 
this means, the arsenic is dissolved as sodium arsenate, 
and can be filtered nearly pure. " Magnesium mixture" 
is now to be added to the solution directly, and the 
analysis conducted as above. 

To insure the purity of the precipitate, it is well to dis- 
solve it in nitric acid, filter out any insoluble residue, 
which is to be deducted, and also to test for phosphoric 
acid, which, if found, is also to be deducted. 



Note. — Where the percentage of arsenic in the ore will probably amount to 20 
or 25 per cent., it is usually advisable when the molybdate separation is used, to 
make the solution from 1 gm. up to some convenient bulk, and to take some 
fraction, as one-half or one-quarter, for the determination. 



CHAPTER XXVI. 

ANTIMONY ORE. 

To determine the antimony, add, to 1 gm. of the finely 
pulverized ore, 5 c. c. of concentrated nitric acid, 10 c. c, 
of concentrated hydrochloric acid, 3 gms. of tartaric acid,, 
and heat on a water-bath until the substance is nearly dry 
in order to expel most of the free acid. Then dilute with 
100 c. c. of water, make alkaline with ammonia, add 8 
or 10 c. c. of yellow ammonium sulphide, and warm 
gently for an hour. Enough of the alkaline sulphide 
should be added to make the fluid yellow. Filter 
and wash with hot water until the washings run 
through the filter perfectly colorless. The filtrate will 
contain the antimony as ammonium sulph-antimonate. 
Acidulate the filtrate with hydrochloric acid, and allow 
the precipitate of antimony sulphide to settle completely. 
Dry the residue remaining upon the filter, fuse it with 4 
or 5 gms. of sodium carbonate, and 1 gm. of sodium nitrate, 
treat the fused mass with an excess of hydrochloric acid 
and about 1 gm. of tartaric acid, evaporate off excess of 
acid as above, add 25 c. c. of water, make alkaline with 
ammonia, treat with yellow ammonium sulphide, filter, 
wash, acidulate the filtrate with hydrochloric acid, and, 
should any antimony sulphide be precipitated, allow it to 
settle as directed before. Filter out the precipitates of an- 
timony sulphide on the same filter, wash with hot water, 
then with alcohol to displace the water adhering to the 
precipitate, dry it at a low heat, wash with carbon disul- 
phide, to dissolve the free sulphur, and dry at a tempera- 
ture not over 100° C. The heat should be moderate, and 
continued no longer than is necessary. When the precip- 
itate is dry enough to be removed from the filter, brush it 
into a clock-glass, cleaning the paper as thoroughly as pos- 



ANTIMONY. 158 

sible, and place the filter in a capacious weighed porcelain 
crucible, furnished with a cover. Moisten it with ordinary 
concentrated nitric acid, add 4 or 5 c. c. of red fuming nitric 
acid, and evaporate on a water-bath to dryness. Then 
transfer the precipitate to the crucible, add a little concen- 
trated nitric acid cautiously by means of a pipette, insert- 
ing the point of the pipette under the edge of the lid. 
When the violent action is over, add also to the precipi- 
tate 8 or 10 times its volume of red fuming nitric acid, ob- 
serving the same precautions as before, and evaporate to 
dryness on a water-bath, having removed the cover from 
the crucible as soon as all danger of loss by spirting is past. 
Finally, ignite cautiously over a Bunsen burner, to expel 
the sulphuric acid, and convert the precipitate into anti- 
mony tetroxide (Sb 3 4 ), from which calculate the anti- 
mony. This method is due to Bunsen. (See Fres., Quant. 
Anal., § 125, 2, b, p. 243.) All the filtrates should be 
treated again with sulphuretted hydrogen, to recover any 
possible traces of antimony which may have escaped pre- 
cipitation before. 



CHAPTER XXVII. 

TYPE METAL. 

The metals to be looked for are antimony, lead, tin, 
and iron. In rare cases, a little arsenic may be present. 

To 1 gm. of the metal, comminnted, by drilling, shav- 
ing, or filing, add 3 or 4 gms. of tartaric acid, and 20 c. c. 
of dilute nitric acid, prepared by mixing 1 part of con- 
centrated nitric acid with 2 parts of water. Digest on a 
water-bath until excess of nitric acid is entirely expelled, 
add 50 c. c. of water, excess of ammonia, 10 c. c. of 
yellow ammonium sulphide, and allow to stand on a 
water-bath for 3 or 4 hours, the water in the bath being 
heated to a point just below boiling. Do not heat strong- 
ly. Dilute to about 100 c. c, filter, and wash with water 
until the washings are colorless. The oxides of antimony 
*and tin go into solution as ammonium sulphantimonate 
and sulpho-stannate, while the lead and iron sulphides 
remain on the filter undissolved. Wash the contents 
of the filter, dry the filter, burn it in a porcelain crucible, 
after moistening with nitric acid, add to the ash 5 or 6 
drops of nitric acid, warm, and wash it into the casserole. 
Then add 6 or 7 c. c. of nitric acid and 2 or 3 c. c. of sul- 
phuric acid, and heat until fumes of S0 3 appear ; cool, 
add 50 c, c. of water, filter, and wash with 40 or 50 c. c. of 
water containing 1 per cent of sulphuric acid. Dry the 
filter and contents, transfer the latter to a clock-glass, 
place the filter in a capacious weighed porcelain crucible, 
add 8 or 10 drops of nitric acid and 4 or 5 drops of sul- 
phuric acid, evaporate off the excess of acid, and ignite. 
Again add 4 or 5 drops of nitric acid and 1 or 2 drops of 
sulphuric acid, expel excess of acid, transfer the contents 
of the filter from the clock-glass to the crucible, ignite all, 



ANTIMONY. 155 

cool, weigh the lead sulphate, and calculate the per cent 
of lead. (Consult analysis of galena. ) 

Acidify the alkaline filtrate containing the tin and anti- 
mony, and perhaps some arsenic, with hydrochloric acid, 
und allow the sulphides to settle in a warm place, avoid- 
ing great heat. Then filter, wash with water, displace the 
water with a little alcohol, dry at a moderate heat, run a 
little carbon disnlphide through the filter, to dissolve out 
free sulphur, expel excess of carbon disnlphide at gentle 
heat (better in a steam-bath), place the filter and contents 
in a large porcelain crucible, add 1 or 2 c. c. of nitric acid, 
and cover with a glass. When the violent action is over, 
add 4 or 5 c. c. of red fuming nitric acid, and evaporate at 
a gentle heat nearly to dryness to convert the sulphides 
into oxides. Then neutralize the remaining acid with 
pure sodium hydrate, wash the oxides into a silver dish 
with water containing a little sodium hydrate (using as 
little as possible), evaporate nearly to dryness, add about 
8 parts of pure sodium hydrate, and a little sodium ni- 
trate, continue the evaporation to perfect dryness, and fuse. 
As soon as the mass is fused, remove the heat, and when it 
is cool enough add 100 c. c. of hot water, and boil until 
the contents of the dish are pulverulent. Finally, cool, 
add alcohol to the amount of one third the volume of the 
fluid, filter, wash the residue with dilute alcohol (prepared 
by mixing 1 part of alcohol with 2 parts of water), to 
which has been added a few drops of strong solution of 
sodium carbonate. The insoluble sodium antimonate will 
remain on the filter, while the sodium stannate and 
sodium arsenate go into solution. Wash the antimonate 
from the filter into a beaker with water, place the beaker 
under the filter, and pour through the latter 10 or 15 c. c. 
of warm concentrated hydrochloric acid, containing 1 gm. 
of tartaric acid, wash with a little water, and warm until 
everything is dissolved. Dilute the solution to 100 c. c, 
saturate it with sulphuretted hydrogen, filter, wash, treat 
the precipitate as directed in the analysis of antimony ore, 



156 TYPE METAL. 

and calculate the per 'cent of antimony. (See Fres., 
Quant. Anal., % 165 — 4— a, p. 398.) 

Should there be no arsenic present, acidify the nitrate 
containing tin with hydrochloric acid, and saturate with 
sulphuretted hydrogen. Heat, filter, wash with solution 
of ammonium acetate, containing a little free acetic acid, 
dry, roast at gentle heat in a weighed porcelain crucible, 
then heat strongly, cool, weigh the stannic oxide, and cal- 
culate the per cent of tin. (See analysis of tin ore. ) Puri- 
fy the weighed precipitate as in analysis of bronze. Should 
arsenic be present, it will be found, together with the tin, 
in the filtrate from the sodium antimonate, after the fusion 
with sodium hydrate. Add to the filtrate 1 or 2 c. c. of 
ammonia, and 2 or 3 c. c. of yellow ammonium sulphide, 
and warm gently for a short time. Then add 5 c. c. of 
" magnesium mixture," and allow to stand for 12 hours. 
Filter out the magnesium-ammonium arsenate, treat it 
as directed in the analysis of arsenic ore, and calculate 
the per cent of arsenic. 

Acidify the filtrate from the magnesium arsenate with 
hydrochloric acid, precipitate the tin as sulphide, and pro- 
ceed to determine it as directed above. 

The filtrate from the lead sulphate will contain the iron. 
Precipitate the iron as basic acetate, filter, wash moder- 
ately, dissolve the precipitate in hydrochloric acid, re-pre- 
cipitate with ammonia, filter, wash, dry, ignite, weigh the 
ferric oxide, and calculate the per cent of iron. 

Examine the filtrate for other metals of Group IV., 
and, if found, determine them. (H. Will, Anleitung f. 
Anal Chem., 225, Ed. 1857.) 



CHAPTER XXVIII. 



REFINED LEAD. 



Determine silver in separate portion. Note 1. 
For other metals, dissolve 200 gms. in nitric acid. 



Note % 



Residue (a). 
Sb,S:n. Add to pre- 
cipitate (r). Note 2. 



Solution (a). 
Add sulphuric acid. Note 3. 



Residue (b). 
PbS0 4 . Noted. 



Solution (b). 
Evaporate. Note 3. 



Precipitate (c). 
PbS0 4 . Note 4. 



Filtrate (d). 

Reject. 
Note 4. 



Free. (d). 

Add to 

Precipitate 

(/). Note 4. 



Precipitate (g). 
Fe,Zn,Co,Ni. Note 7. 



Jtesidue (h). 

Co,Ni. 
Notel. 



Prec. (i). 
Fe. Note 8. 



Solution (j). 
Note 9. 



Solution (h). 

Fe.Zn. 
Note 8. 

Solution (i). 
Note 9. 

Prec. (j). 
JVofe 9. 



Precipitate (o). 
Cd. iVbfe 11. 



Solution (x). 
Note 11. 



Solution (c). 
Dilute and pass H 2 S. iVbte 5. 

Solution (/). Precipitate (/). 

Evaporate to 500 c. c 
iVbfe 6. 



Solution (g). 



Prec. (Jc). 

Add to 

precipitate 

(g). NoteG. 



Solution (k). 

Reject. 
Note 6. 



Solution (m). 
iVbfe 11. 



Solution (n) 

Cd, etc. 
Note 11. 

Filtrate (o). 

Note 11 



Prec. (n). 
Bi. iVb*e 
11. 



Precipitate (x). 
Note 11. 



Sb,As,Sn,Bi,Cu,Cd, 
Pb. Add precipitate (d). 
Note 10. 



Residue (l). 

Bi,Cu,Cd, 
Pb. Note 10. 
Prec. (m). 

Reject. 
Note 10. 



Solution (s). 

As,Sb,Sn. 
Note 12. 

Prec. (*). 

As,Sb,Sn. 
Note 12. 



Solution (I). 
As,Sb,Sn. 
Note 10. 



Note 
10. 



P. (r.) 

Sb, 

As,Sn 

iV. 12. 



Residue (s). 
Note 12. 



Filtrate (t). 

Reject. 
!iVb*el2. 



As. 



Solution (u). 
Note 12. 



Sb,Sn. 



Residue (u). 
Notes 13 and 14. 



Compare Fres., Zeit. fur An. Chem., Yol. VIII. , 1869. 
The lead may contain silver, copper, bismuth, cadmium, 
zinc, iron, nickel, cobalt, arsenic, antimony, tin, manga- 
nese. 

Note 1. — The silver may be determined either by cupel- 
lation, or by a wet method. If the latter plan is adopted, 
weigh 200 gms. of pieces, scraped clean, introduce them 



158 REFINED LEAD. 

into a i. 5-litre flask, add nitric acid of 1.2 sp. gr., in small 
portions at a time, always keeping the metal in excess, 
and heat the liquid nntil only about 5 or 10 gms. of lead 
remain undissolved, and the solution begins to turn yellow 
in consequence of the formation of lead nitrite. The silver 
will be concentrated in the residual metal. Withdraw it 
from the solution, and dissolve it in nitric acid, dilute to 
200 c. c.j and add a mixture of 1 c. c. of hydrochloric acid 
and 50 c. c. of water. Allow the whole to stand 2 or 3 
days, and after all the silver chloride has settled, draw off 
the clear fluid, and filter out the silver chloride, on a small 
filter, wash with hot water, dry, and ignite filter and pre- 
cipitate together in a small weighed porcelain crucible. If 
the amount of silver chloride is so considerable that there 
is a possibility of its being incompletely reduced by the 
combustion of the filter-paper, the residue must be heated 
for a few minutes in a stream of hydrogen before weigh- 
ing. The amount left, after subtracting the filter-ash, 
gives the quantity of silver in the 200 gms. of lead. The 
refined metal seldom contains more than 0.0015 per cent 
of silver. 

Instead of treating the ignited precipitate with hy- 
drogen, add about 0.5 c. c. of nitric acid, evaporate to 
dryness, again add 0.5 c. c. of nitric acid, heat to dissolve 
any reduced silver, add 8 or 10 drops of hydrochloric acid, 
evaporate to dryness, fuse the silver chloride, cool, weigh, 
and calculate the silver. (See analysis of barium chloride. ) 

Note 1 '!. — For the main analysis, weigh 200 gms. of lead, 
cleaned as before, introduce it into a 2-litre flask, add 500 
c. c. pure nitric acid of 1.2 sp. gr. and 1 litre of water, and 
allow it to stand for 24 hours. Should a residue (a) con- 
taining antimony and tin remain, filter it out, dissolve it 
in hydrochloric acid, dilute a little, pass sulphuretted 
hydrogen through the solution, filter out the precipitate, 
wash, and reserve it to go with precipitate (r), consisting of 
the sulphides of antimony, arsenic, and tin. 

Note 3. — Transfer the clear solution (a) to the 2-litre flask. 



ANTIMONY — METALS OF GEOUPS IV. AND V. 159 

if not already there, add 65 c. c. of pure concentrated sul- 
phuric acid, shake, cool, fill up to the 2-litre mark, agitate 
again, and allow to settle. Then siphon off accurately 
1750 c. c. of the clear solution, and reject the rest contain- 
ing lead sulphate or residue (b). It has been found, by 
repeated experiments, that the lead sulphate from 200 
gms. of lead occupies 44.99 c. c, or, in round numbers, 45 
c. c. The 2-iitre flask, when filled to the mark, will hold, 
then 1955 a c. of solution and 45 c. c. of lead sulphate. 
But as 1955 c. c. of the solution correspond to 200 gms. of 
the lead, then 1750 c. c. of solution will correspond to 
179.03 gms. of the original lead, or, in round numbers, 179 
gms. Consequently, all the calculations must be based 
upon this as the quantity taken for analysis. Evaporate 
the 1750 c. c, or solution (&), to fumes of S0 3 , allow to cool, 
add 60 c. c. of water, filter off and wash precipitate (c) of 
lead sulphate, containing, perhaps, a little antimony. 

Note 4. — Dissolve precipitate (c) in hydrochloric acid, 
add 10 volumes of sulphuretted hydrogen water, warm, 
pass sulphuretted hydrogen gas, allow the precipitate to 
settle, filter, wash, spread filter in a porcelain dish, heat 
with a solution of yellow sulphide of ammonium or potas- 
sium, to which a little pure sulphur has been added, filter, 
wash, acidify the filtrate with hydrochloric acid, allow the 
precipitate to settle at a gentle heat, filter, and wash. 

Keject the filtrate, or filtrate (d), and add the precipitate, 
or precipitate (d\ to precipitate (/). If precipitate id) 
contains much lead, treat it again with ammonium or po- 
tassium sulphide, as before, filter, acidulate with hydro- 
chloric acid, allow the antimony sulphide to settle, filter, 
and add the pure antimony sulphide to precipitate (f). 

Note 5. — Dilute solution (c), the filtrate from precipitate 
(c) of lead sulphate, to 200 c. c, heat to 70° C, pass the 
sulphuretted hydrogen, allow to stand 12 hours over a 
very gentle heat, filter through a small filter, and wash 
with hot water. There will be a solution (/), which may 
contain iron, zinc, cobalt, nickel, and manganese, and a 



160 EEFINED LEAD. 

precipitate (/), which may contain antimony, arsenic, tin, 
bismuth, copper, cadmium, and lead. 

Note 6. — Evaporate solution (/) to a volume of about 400 
c. c, transfer to a half -litre flask, make alkaline with am- 
monia, mix with freshly -prepared ammonium sulph-hy- 
drate, fill the flask, and allow to stand 24 hours. When 
the precipitate (g) has settled, filter, acidify the filtrate, or 
solution (g), with acetic acid, and boil to recover any 
nickel which may have been retained in the solution. 
Filter out precipitate (7c) of nickel sulphide, and, after 
washing it slightly and drying, add it to precipitate (g), 
which contains the principal part of the nickel, and reject 
the filtrate, or solution (Jc). 

Note 7. — Treat precipitate (g), containing, perhaps, iron, 
zinc, nickel, cobalt, and manganese, on the filter, with a 
mixture of 1 part of hydrochloric acid of sp. gr. 1.12, and 
6 parts of sulphuretted hydrogen water, pouring back the 
filtrate repeatedly on the filter, to avoid increasing the vol- 
ume of fluid unnecessarily. Burn the filter containing resi- 
due (h), after drying, together with the filter, containing pre- 
cipitate (7c), in a porcelain crucible, treat with nitro-hydro- 
chloric acid, concentrate the solution, add a little water, 
filter, wash, make the filtrate alkaline with ammonia, add 
a few drops of ammonium carbonate, filter into a platinum 
dish, treat the filtrate with a few drops of strong solution 
of potassium hydrate, and heat until ammonia is entirely 
expelled. Then filter off the slight flocculent precipitate, 
wash, dry, ignite, and weigh the nickel oxide, and calcu- 
late metallic nickel. (See analysis of nickel ore.) Test 
the precipitate with the blow-pipe for cobalt. 

Note 8. — Add a few drops of nitric acid to solution (h\ 
containing the iron and zinc, concentrate, make alkaline 
with ammonia, filter off the ferric hydrate, or precipitate 
(i), dissolve the precipitate with a few drops of hydro- 
chloric acid, again precipitate with ammonia, filter, wash, 
dry, ignite, weigh the ferric oxide, and calculate metallic 
iron. To verify the results, fuse the precipitate with acid 



ZINC — MANGANESE — GROUP VI. 161 

sodium sulphate, dissolve in water, reduce with zinc and 
platinum, and determine the iron with a dilute solution of 
potassium permanganate. (See analysis of ammonia-iron- 
alum.) 

Note 9. — Mix solution (i), or the filtrate from the ferric 
hydrate, with a little ammonium sulph-hydrate in a small 
flask, and allow to stand for 24 hours in a warm place. 
Filter out precipitate (J), wash and digest on the filter with 
dilute acetic acid, to dissolve out any manganese sul- 
phides. Dissolve the residue of zinc sulphides remaining 
on the filter with hydrochloric acid, boil, after adding a 
little potassium chlorate to oxidize the sulphur, precipi- 
tate the zinc with sodium carbonate, and from the ignited 
precipitate calculate the zinc. (See analysis of zinc ore.) 

Boil solution (J), or the acetic acid solution of manganese 
sulphide, to small volume, add a little bromine water, 
warm until the excess of bromine is expelled, filter, wash 
with hot water, dry, ignite the precipitate, and calculate 
the manganese. (See analysis of manganese ore.) 

Note 10. — Heat precipitate (f\ which may contain anti- 
mony, arsenic, tin, copper, bismuth, cadmium, and lead, 
after adding precipitate (/), with a solution of potassium 
sulphide, to which some pure sulphur has been added, 
filter out residue (?), which may contain bismuth, copper, 
cadmium, and lead, and wash with hot water. Acidulate 
the filtrate, or solution (I), which may contain arsenic, an- 
timony, and tin, with hydrochloric acid, and allow the pre- 
cipitate to settle completely. Filter out precipitate (r), 
which may contain arsenic, antimony, and tin, and reject 
the filtrate, or solution (r). 

I Heat residue (Z), (insoluble in potassium sulphide) nearly 
to boiling, in a porcelain dish, with dilute nitric acid (pre- 
pared by mixing 1 part of acid of 1.2 sp. gr. with 12 parts 
of water). When the precipitate is dissolved, filter, wash 
the paper slightly, dry, ignite it, and add the ash to the 
nitric-acid solution. Then add 2 c. c. of dilute sulphuric 
acid, evaporate to fumes of S0 3 , dilute a little, and filter 



162 KEFINED LEAD. 

out and wash precipitate (m) of lead sulphate, which may 
be rejected. (See analysis of galena.) 

JVote 11. — Nearly neutralize solution (m) (or the filtrate 
from the lead sulphate, and which may contain bismuth, 
copper, cadmium, and silver), with pure potassium hydrate, 
add !N"a 3 C0 3 and a little of a solution of pure potassium cy- 
anide free from potassium sulphide, and heat gently. If 
a precipitate (n) of bismuth hydrate is produced, filter it 
out, wash, dissolve it in dilute nitric acid, precipitate it 
with ammonium carbonate, weigh it as bismuth trioxide 
(Bi 2 3 ), and calculate the metallic bismuth. (See Fres., 
Quant. Anal. § 120.) To solution (n) add a little more po- 
tassium cyanide and a few drops of potassium sulphide, 
filter and wash the precipitate (o) of sulphides of cadmi- 
um and silver, dissolve in dilute nitric acid, add a little 
hydrochloric acid, filter out and wash the precipitate of 
silver chloride or precipitate (x), which may be rejected, 
as the silver is determined elsewhere. Evaporate solution 
x), containing cadmium, nearly to dryness, add a few 
drops of solution of sodium carbonate, filter out the pre- 
cipitate of cadmium carbonate, wash, dry, ignite, and 
weigh the cadmium oxide, and from it calculate metallic 
cadmium. To prevent reduction and volatilization of cad- 
mium during the ignition, moisten the filter with solution 
of ammonium nitrate. 

If no precipitation of the cadmium is produced by the so- 
dium carbonate, add a little potassium hydrate, and if one 
then forms, filter, wash, and proceed as above. Mix the 
filtrate from the sulphides of silver and cadmium, or filtrate 
(o), with a small quantity of nitric and sulphuric acids, and 
evaporate nearly to dryness. Then add a few drops of hy- 
drochloric acid, and heat until cyanogen is expelled. Fil- 
ter, if necessary, and determine the copper by one of the 
methods given in the analysis of copper ore. 

"When cadmium is absent, the separation of the bismuth 
and copper may be effected by means of ammonia and am- 
monium carbonate, removing any silver by hydrochloric 



METALS OF GKOUP VI. 16& 

acid before precipitating copper sulphide. (For precau- 
tions to be observed, see Fres., Quant. Anal., § 163, 5.) 

Note 12. —To precipitate (r), which may contain arsenic, 
antimony, and tin, and which was obtained by acidifying 
the potassium sulphide solution (T) with hydrochloric 
acid, add the sulphuretted hydrogen precipitate from the 
solution of residue (a), (see Note 2), dry, and treat repeat- 
edly with carbon disulphide. After the carbon disulphide 
has evaporated from the filter, warm it, with its contents, in 
a covered porcelain crucible, after adding a few drops of 
red fuming nitric acid, heat the solution cautiously to expel 
excess of nitric acid, add sodium carbonate in excess and a 
little sodium nitrate, evaporate to dryness, and heat until 
the mass melts, and becomes white. Transfer the fused 
mass to a small mortar, add a little water, and pulverize 
carefully. Then wash it into a breaker, and proceed as di- 
rected in the analysis of type metal. (See also Fres., 
Quant. Anal., page 427.) 

Dissolve residue is) of sodium antimonate, in hydro- 
chloric and tartaric acids, pass sulphuretted hydrogen, set 
aside for a few hours, filter out antimony sulphide, wash, 
dry the precipitate, and reserve it to be combined with, 
the sulphuretted hydrogen precipitate from the solution 
of residue (u). 

Evaporate solution (s), which may contain arsenic, anti- 
mony, and tin, in order to expel alcohol, add excess of di- 
lute sulphuric acid, evaporate to expel nitric acid, add 
water, heat to 70° C, and pass sulphuretted hydrogen. 
When precipitate {t) has settled, filter, and wash with 
water, and reject the filtrate, or solution (t). If no tin be 
present, treat precipitate (t), on the filter, with a cold con- 
centrated solution of ammonium carbonate, pouring the 
filtrate back on the filter repeatedly in order to avoid the 
use of a large excess of solution of ammonium carbonate. 
The ammonium carbonate solution (u) will contain the 
arsenic. Acidulate it with hydrochloric acid, add a little 
filtered sulphuretted hydrogen water, filter through a 



164 REFINED LEAD. 

small tube, in which a little asbestos has been placed, 
both having been previously heated and weighed. When 
the whole of the precipitate has been transferred to the 
little tube, heat it at 100° C, until the greater portion of 
the water is expelled, and then heat it gently, not much 
above 100° C, in a stream of dried carbon dioxide, 
allow it to cool in a current of the gas, displace the 
carbon dioxide with atmospheric air, and weigh the tube 
and contents, and, from the trisulphide, calculate the 
arsenic. A better plan is to filter out the arsenious sul- 
phide on a very small filter, oxidize the filter and sul- 
phide together by evaporation with fuming nitric acid, 
fuse the residue in platinum with a little sodium carbon- 
ate and nitrate, dissolve in water, and weigh the arsenic 
as magnesium pyro-arsenate, as directed in the analysis of 
arsenic ore. 

Note 13. — Dissolve residue (u) containing antimony, to- 
gether with the precipitate from solution of residue (s), in 
strong hydrochloric acid, pass sulphuretted hydrogen, 
filter through a small tube in the same way as directed 
above in the case of arsenic, heat gently in a stream of 
dried carbon dioxide, until the antimony trisulphide turns 
black, cool in a current of the gas, displace the latter by a 
current of dry air, weigh the tube and contents, and cal- 
culate the antimony. Or, oxidize the antimony oxide 
by Bunsen's method with nitric acid, and weigh it, as 
directed in the analysis of antimony ore, as antimony 
tetroxide. 

Note 14. — If tin be present, after expelling alcohol, 
passing sulphuretted hydrogen, and filtering out the pre- 
cipitate, dissolve the latter in potassium sulphide, add ex- 
cess of sulphurous acid, digest for some time on a water- 
bath, and then boil until two thirds of the water, and all 
the sulphurous acid are expelled. Solution if) will con- 
tain all the arsenic. (See Bunsen, in Annal. d. CJiem. u. 
Pharm., 106, 3, and Fres., Quant. Anal., §165-6.) 

Precipitate the arsenic as sulphide, oxidize, fuse, take 



TIN — SULPHUK. 165 

up with water, and weigh the arsenic as magnesium pyro- 
arsenate, as directed in the analysis of arsenic ore. 

Residue (t) will contain the tin and antimony. Oxidize 
it with fuming nitric acid in a weighed porcelain crucible, 
and weigh. Then ignite in a stream of hydrogen to expel 
the antimony tetroxide, oxidize again with nitric acid, and 
weigh the stannic oxide, from which calculate the tin. 
Calculate the antimony from the loss of antimony tetrox- 
ide. The tin and antimony may be separated and de- 
termined by oxidizing the residue left after extracting the 
arsenic, with nitric acid, fusing, dissolving in water, filter- 
ing out the soluble stannate from the insoluble antimon- 
ate, which latter is to be dissolved in hydrochloric and tar- 
taric acids, precipitated as sulphide, and the sulphide 
oxidized and weighed as antimony tetroxide, as directed 
in the analysis of antimony ore. 

To determine the tiu 3 precipitate the sulphide from the 
solution of stannate, by means of sulphuretted hydrogen, 
filter it out, and burn it to stannic oxide, as directed in 
the analysis of tin ore. 

Note 15. — To determine the small quantity of sulphur 
which may be present in the lead, draw out a piece of 
combustion tubing about 1 metre long, and of about 2 
centimetres diameter, to a long point, which is bent down 
so as to dip into a small 3-bulbed U tube filled with water. 
Also narrow the combustion tube in the middle, so as to 
form a kind of bridge. Introduce into the anterior end of 
the tube about 100 gms. of the lead, in the form of a rod 
of about 1 centimetre diameter, close the tube with a com- 
mon cork, connect it with a smaller tube containing frag- 
ments of charcoal, and place it in a combustion furnace. 
Then heat the charcoal to the point of ignition, and pass a 
current of chlorine. When the tubes are filled with 
chlorine, melt the lead carefully, the tube being so in- 
clined that the melted lead will flow against the bridge, 
but not over it, and not flow back against the cork. Keep 
the charcoal red hot to remove any oxygen from the 



166 EEFINED LEAD. 

chlorine. Regulate the heat so that the lead will burn 
slowly to lead chloride, and collect in the empty part of 
the tube. If the stream of chlorine is properly regulated, 
and the lead chloride not heated, very little of it will pass 
over into the U tube. Wash the contents of the U tube 
into a beaker, precipitate the S0 3 with barium chloride as 
usual, and calculate the sulphur. 



CHAPTER XXIX. 



WHITE PAINT GROUND IN OIL. 

Extract the oil. Note 1. The dry paint may contain 
BaS0 4 , PbS0 4 , CaS0 4 , 2PbC0 3 — PbH 2 2 , BaC0 3 , CaC0 3 , ZnO, 
PbO,Si0 2 ,Al 2 ,(Si0 3 ) 3 . Note 2. 



Residue (a). 
BaS0 4 ,PbS0 4 ,CaS0 4 ,Si0 2 ,Al 2 



(Si0 3 ) 3 . 
Residue (b). 
BaS0 4 ,PbC0 3 , 
CaC0 3 ,Si0 2 ,Al 2 
(Si0 3 ) 3 . Note 4. 

Residue (c). 
BaS0 4 ,Si0 2 ,Al 2 
(SiO s ) 3 . Notes 5 
and 6. 

Precipitate (d). 
PbS. Note 7. 



Note 3. 

Filtrate (b). 
(NH 4 ) 8 S0 4 . I 
may be rejected 
Note 3. 



Solution (c). 

Pb(C 2 H 3 2 ) 2 , 
and Ca(C 8 H 8 2 ) 8 . 
Note 7. 

Solution (d). 

Ca(C 2 H 3 2 ) 2 . 
Note 8. 



Solution (a). 

Pb(C 8 H 3 2 ) 2 ,Zn(C 2 H 3 2 ) 2 ,Ca(C 3 H, 

2 ) 2 ,Ba(C s H s 3 ) a . iVb^e 9. 



Precipitate (e). 
PbS,ZnS. iVofe9. 



Res. (/). 
PbS0 4 . 

iVbfe 9. 



Filt. (/). 
ZnS0 4 . 
iVofe 10. 



Filtrate (e). 
Ca(C 2 H 3 2 ) 2 ,Ba 
(C 8 H 3 8 ) 2 . Note 
11. 

Prec. (g). Filt. (g). 
BaS0 4 . Ca(C 2 H 8 
Note 11. 2 ) 8 . 
Note 12. 



The paint may contain, besides the oil, one or more of 
the following constituents, namely : Sulphates of lead, 
barium, and calcium ; carbonates of lead, barium, and cal- 
cium ; oxides of lead and zinc, and also silica and clay. 

Make a careful qualitative analysis of the paint, after 
extracting the oil, for upon it will depend the character 
of the quantitative analysis. 

Notel. — Weigh a clean dry flask, which holds about 
150 c. c.j and introduce into it 3 or 4 gms. of the paint, 
and note the weight. Then add 30 or 40 c. c. of ether or 
gasoline, shake well, and heat over steam until the fluid 
boils. Allow the solid matter to settle, and decant the 
clear fluid on a dny filter without disturbing the residue 
more than is necessary. Repeat the operation with 25 or 
30 c. c. of the solvent. Finally, wash the contents of the 



168 PAINT. 

flask on the filter with 25 or 30 c. c. of ether or gasoline, 
and dry the filter and contents, in an air-bath, at 100° C. 
The quantitative analysis may be made of a portion of 
this. 

To determine the oil, evaporate the filtrate in a weighed 
dish, without application of heat, until only oil is left, 
and then in an air-bath, at a temperature of 100° C, for 
about an hour, cool, and weigh. Should there be any 
water in the oil, as there may be, if the ether used was not 
perfectly anhydrous, continue to heat at 100° C. until it is 
expelled, and then cool and weigh. Should the filtrate be 
turbid, and not cleared by refiltering, as is sometimes the 
case, pour it into a measured flask, dilute to a known 
volume, dilute with ether or gasoline, as the case may be, 
cork, and set it aside. After the solid matter has settled, 
take an aliquot portion of the clear fluid, evaporate it in a 
weighed dish, as directed above, and calculate the per cent 
of oil. The proportion of solid matter will be too small to 
render it necessary to make the allowance for its volume, 
as in the case of refined lead. 

Note 2. — Weigh carefully 1 gm. of the dry residue, 
from which the oil has been thoroughly extracted, and 
dissolve it in about 25 c. c. of hot acetic acid, in a covered 
vessel. Filter, and wash with hot water. 

If there be any residue (a) left on the filter, it will con- 
tain the silica and clay, and sulphates of barium calcium 
and lead, that may be present in the paint. 

Solution (a) may contain lead, zinc, calcium and barium 
in the form of acetates, the last being due to the use of 
witherite (barium carbonate). 

Note 3. — Treatment of residue (a) : 

Wash it from the filter into a beaker with water, add 8 
or 10 gms. of ammonium carbonate, plug the point of the 
funnel, and fill also with a strong solution of ammonium 
carbonate, placing it in a filter-stand over the beaker, and 
allow all to stand for 12 hours, with frequent stirring. 
By this means, the sulphates of lead and calcium will be 



BARYTES, ETC. 169 

converted into carbonates, while the barinm sulphate, 
silica, and clay will remain unaltered. Then remove the 
plug from the point of the funnel, allow the fluid in the 
filter to run through into a second beaker, pour the solu- 
tion of ammonium carbonate, from the first beaker, on the 
same filter, also transfer to it residue (b) (which may con- 
tain sulphate of barium, carbonates of calcium and lead, 
and silica and clay), and wash well with hot water. The 
filtrate and washings, or filtrate (b), will contain the sul- 
phuric acid, which was combined with calcium and lead, 
and may be rejected. (See note on galena analysis, p. 144.) 

Note 4. — Pour through the filter containing residue (b) 
(or the carbonates of calcium and lead, the sulphate of 
barium, and the silica and clay), hot acetic acid until it 
produces no effervescence, and wash well with water. 

Residue (c) will contain any sulphate of barium, silica, 
and clay, while filtrate (c) will contain any acetates of lead 
and calcium. 

Note 5. — Dry, ignite, and weigh residue (c). Then fuse 
it with sodium carbonate, boil the fused mass in water, 
filter, and wash out alkaline sulphate. Treat the residue, 
containing barium carbonate, with hot dilute hydrochloric 
acid, by pouring it through the filter, and wash the latter 
well with hot water, allowing the filtrate and washings to 
run together into a separate beaker. To the clear acid so 
lution add sulphuric acid, and determine the barium sul- 
phate as usual. This will give the amount of barytes in 
the paint. The difference between this weight and that of 
the total residue (c) will give the amount of silica and 
clay. 

Note 6. — Evaporate nearly to dryness the filtrate from 
the barium sulphate, after washing into it any residue 
left upon the filter, after dissolving the barium carbonate, 
transfer to a platinum crucible, add some acid sodium sul- 
phate, and fuse. When the mass is cool enough, add a 
little sulphuric acid, heat until the mass is brought to a 
pasty consistence, cool, and dissolve in water. By this 



170 PAINT. 

mea ns, the silica will be rendered insoluble, and the alumina 
dissolved. Filter out and weigh the silica ; precipitate 
the alumina with ammonia, and determine it as usual. 
Calculate the alumina to clay (Al 2 (Si0 3 ) 3 ). Any excess of 
silica is probably due to the use of infusorial earth. 

Note 7. — Saturate the nitrate from the barium sulphate, 
clay, and silica, or acetic acid solution (c), with sulphu- 
retted hydrogen, filter out the lead sulphide, or precipi- 
tate (d), and wash it with a little sulphuretted hydrogen 
water. Then wash the precipitate from the filter into a 
beaker, dry the filter, transfer it to a porcelain crucible, 
moisten it with nitric acid, burn it, add the ash to the 
precipitate, and dissolve all with nitric acid. Then add a 
little concentrated sulphuric acid, evaporate to fumes S0 3 , 
dilute, filter out, and determine the lead sulphate existing 
as such in the paint. (See analysis of galena.) 

Note 8. — Boil out the sulphuretted hydrogen from the 
filtrate from the lead sulphide, or solution (d), which 
may contain calcium acetate, add excess of ammonia 
and ammonium oxalate, filter, treat the precipitate as 
directed in the analysis of calcite, and weigh the calcium 
sulphate which existed in the paint as such. 

Note 9. — Treatment of solution (a) : 

Solution (a) may contain acetates of lead, zinc, calcium, 
and barium. Saturate with sulphuretted hydrogen, filter 
out, and wash precipitate (e), which may contain sulphides 
of lead and zinc, dissolve the precipitate in nitric acid, 
add sulphuric acid to the solution, evaporate to fumes of 
S0 3 , dilute, filter out the lead sulphate, or residue (/), 
observing the directions given in the analysis of galena, 
and calculate to basic carbonate of lead (2PbC0 3 ,PbH 2 2 ). 
(See Note 13.) 

Note 10. — From filtrate (/), the filtrate from the lead sul- 
phate, precipitate the zinc with excess of sodium carbonate, 
and determine the zinc oxide, as in the analysis of zinc ore. 

After precipitating, and filtering out the zinc carbonate, 
treat the filtrate with sulphuretted hydrogen, to insure 



BARIUM AND CALCIUM CARBONATES, ETC. 171 

the complete x>recipitation of the zinc. Should any zinc 
sulphide be precipitated, dissolve it in hydrochloric acid 
and potassium chlorate, precipitate with excess of sodium 
carbonate as above, and, after determining the amount of 
zinc oxide, add it to the first. 

Note 11. — To the filtrate from the sulphides of lead and 
zinc, or filtrate (e), which may contain acetates of calcium 
and barium, add a little hydrochloric acid, and dilute sul- 
phuric acid, to precipitate any barium present, filter out 
the barium sulphate, and wash it with sodium hyposul- 
phite, to dissolve out any calcium sulphate which may 
possibly be present. Weigh the barium sulphate, and 
calculate it to barium carbonate. 

Note 12. — To the filtrate from barium sulphate, or fil- 
trate {g\ add excess of ammonia, and a sufficient quantity 
of solution of ammonium oxalate, filter wash, dry, con- 
vert the calcium oxalate into sulphate as directed in the 
analysis of calcite, and calculate to calcium carbonate. 

Note 13. — In case there should be any lead oxide in the 
paint not combined with carbonic or sulphuric acid, it will 
be in the acetic acid solution (a), in which case a careful 
determination of the carbonic acid must be made, and, 
after subtracting enough to satisfy the calcium existing 
as calcium carbonate, the remainder should be calculated 
to basic carbonate of lead. Should there be any lead left 
unsatisfied, it is to be calculated to lead oxide. It must 
be remembered, however, that lead sulphate is slightly 
soluble in acetic acid, and a slight excess of lead in solu- 
tion (a) may be due to this cause. 

Appendix 1. — If the qualitative analysis shows the ab- 
sence of sulphates of barium, lead, and calcium, should there 
be any residue left, after dissolving the paint in acetic acid, 
dry, ignite, and weigh it, as it is probably silica or clay, 
or both. Then fuse it with acid sodium sulphate, digest 
the fused mass with sulphuric acid, dissolve in water, 
filter out the silica, and in the filtrate determine the alu- 
mina, and calculate the clay and free silica as in Note 6. 



172 PAINT. 

If no silica or clay, or sulphates of barium, lead, or cal- 
cium be present, acetic acid will dissolve the paint to a 
clear solution, for the analysis of which proceed as directed 
in Notes 9,10, 11, and 12. 

If no silica, or clay, or salts of calcium and barium be 
present, but only carbonate of lead and oxide of zinc, the 
paint may be dissolved in dilute nitric acid, and the solu- 
tion, after adding sulphuric acid, treated for lead, as 
directed in analysis of galena ; the lead calculated to basic 
carbonate (white lead), and the zinc precipitated from the 
filtrate by sodium carbonate, determined as in the analysis 
of zinc ore, and calculated to oxide. 

If the paint be a pure lead paint, dissolve in nitric acid, 
and determine the lead by evaporating with sulphuric 
acid, and proceeding as directed in the analysis of galena. 
The lead is to be calculated to basic carbonate. 

If it be a simple zinc paint, dissolve in nitric acid, pre- 
cipitate the zinc directly with sodium carbonate, and weigh 
it as oxide, as in analysis of zinc ore. 

In all cases where zinc is precipitated by sodium car- 
bonate, treat the filtrate with sulphuretted hydrogen, and 
if any zinc sulphide be recovered, filter it out, dissolve in 
hydrochloric acid, precipitate with sodium carbonate, and 
add the precipitate to the first one. 

Appendix 2. — In paint composed of sulphate and oxide 
of lead, and containing no carbonate, after dissolving in 
acetic acid, filtering, and washing well, dry, ignite as 
directed in analysis of galena, and weigh the lead sul- 
phate. 

In the acetic acid solution, determine both the lead and 
sulphuric acid, as a small amount of lead sulphate may be 
dissolved by the acetic acid. Calculate the sulphuric acid 
to lead sulphate, and add it to that found in the residue. 
Deduct the amount of lead due to lead sulphate, from the 
total lead found in the acetic acid solution, and calculate 
the remainder to lead oxide (PbO), existing as such in the 
paint. 



CHAPTER XXX. 

FRESH WATER. 

The kind of analysis required depends upon the use to 
be made of the water, whether for drinking and general 
domestic purposes, for steam boilers, for manufacturing 
purposes, or as a mineral water. 

The determination of its value as a potable water can be 
made by a short and simple analysis, showing the amount 
of silica, alumina, and oxide of iron, lime, magnesia, soda, 
potash, chlorine, sulphuric acid, organic and volatile 
matter (expelled by ignition from the residue left after 
evaporating a given quantity of water), and ammonia, 
both free and in a form styled albuminoid, which latter is 
thought to indicate constituents very detrimental to health. 
Besides, it is important to know its hardness, or soap de- 
stroying power. 

This analysis will furnish all the information that is 
requisite to estimate the fitness of water for use in steam 
Iboilers, and for manufacturing purposes. 

The analysis of mineral water is much more complicated 
and laborious, and will be described later. 

Organic and Volatile Matter.- — Evaporate 250 c. c. of the 
water to dryness, in a weighed platinum dish, first on a 
water-bath, and then in an air-bath at 130° C, and re- 
weigh the dish with its contents. Then heat the dish, at 
low-red heat, until all organic matter is consumed, and 
the contents are white or nearly so. Then add 25 c. c. of 
water, saturated with carbon dioxide, evaporate to dry- 
ness on a water-bath, repeat the treatment with carbon 
dioxide, evaporate on a water-bath, dry in an air-bath at 
130° C, as before, cool, and weigh. The difference between 
this weight and the first expresses the amount of organic 
and volatile matter in the quantity of water taken. 



174 WATER. 

In this country it is customary to report analysis of 
water as made on 1 U. S. gallon of 231 cubic inches, con- 
taining a certain number of grains, which number has been 
fixed upon in the Columbia College School of Mines as 
58,318. The weights and measures used are French. This 
involves a short calculation to convert milligrammes into 
the corresponding number of grains. One milligramme is 
one millionth of 1 litre. Suppose that upon evaporating 
1 litre of water 1 milligramme of solid matter was left, the 
quantity will be one millionth of 1 litre. If a gallon of 
the same water were used, the solid matter would amount 
to one millionth of 1 gallon, or, as the gallon is assumed 
to contain 58,318 grains, one millionth of 58,318, and any 
number of milligrammes will correspond to that number 
of millionths of 58,318 grains. Therefore, the number of 
milligrammes multiplied by 58,318 and divided by 1,000,- 
000 will give the number of grains in 1 U. S. gallon of 
231 cubic inches. This rule applies to the calculation of 
all the constituents found by analysis. Then, to deter- 
mine the number of grains of organic and volatile matter 
in 1 gallon of the water under examination, calculate the 
number of milligrammes which would be lost by treating 
the residue left after evaporating 1 litre of the water as 
directed above, multiply this by 58,318, and divide by 
1,000,000. The difference between the weight of dry 
residue before ignition and the sum of the constituents 
found by analysis, allowing for the loss of the water and 
part of the carbonic acid of acid carbonates, should not 
amount to more than a small fraction of a grain. If it 
does, the analysis should be repeated. This remark 
applies only to water containing a small amount of mineral 
matter. In the analysis of mineral waters, if it is desired 
to determine the " total solids " as a check on the correct- 
ness of the analysis, another method is pursued, which 
will be explained later. 

Silica, Lime, Magnesia, Alumina, and Oxide of Iron. — 
To determine these, evaporate in a platinum dish nearly 



-CHLORINE. 175 

to dryness on a sand-bath (finishing the evaporation to 
dryness on a water-bath), from 2 to 8 litres of water, ac- 
cording to the purity of the water, having previously 
acidulated it with hydrochloric acid. Then dry the residue 
in an air-bath at 110° C, until the odor of hydrochloric 
acid cannot be detected, and proceed exactly as directed 
in the analysis of limestone. For this part of the analysis 
of Croton water, 5 litres will be sufficient. The evapora- 
tion may be made in porcelain instead of platinum, but 
there is danger of introducing a small amount of silica and 
alumina into the analysis. As in the analysis of water of 
this character it is unnecessary to separate the small 
amount of alumina and oxide of iron, they are generally 
weighed together, and reported as alumina and ferric 
oxide. 

Sulphuric Acid. — Acidulate from 1 to 4 litres of the 
water with hydrochloric acid, evaporate to about 100 c. c, 
filter, if necessary, and determine S0 3 as in analysis of 
magnesium sulphate. For this determination in Croton 
water, 2 litres will be sufficient. 

Chlorine. — Evaporate from 1 to 4 litres of the water to 
about 100 c. c. (2 litres of Croton water will be sufficient), 
and determine the chlorine volumetrically, by means of a 
standardized solution of silver nitrate. The determination 
is made by first adding to the water 3 drops of a saturated 
solution of potassium chromate, and then dropping into it 
the solution of silver nitrate, from a burette, until the red 
color of silver chromate appears. The number of c. c. of 
silver nitrate solution used, multiplied by the value of 
1 c. c, will give the amount of chlorine. This is calculated 
to grains in a gallon as above. The solution of silver 
nitrate is prepared by dissolving it in distilled water, in 
the proportion of 17 gms. of the pure salt in 1 litre of 
water. To standardize the silver nitrate solution, dissolve 
1 gm. of pure fused sodium chloride in 1 litre of distilled 
water, pour exactly 100 c. c. of the solution into a beaker, 
add 3 drops of saturated solution of potassium chromate, 



178 WATER. 

and drop in, from a burette, the silver solution until the 
red color of silver chromate appears. The Known 
quantity of chlorine, in the 100 c. c. of salt solution, 
divided by the number of c. c. of silver solution used, will 
give the value of 1 c. c. of the latter. In the analysis of 
water containing very little chlorine, it is well to use a 
centime silver nitrate solution. To prepare this, run 10 c. c. 
of the strong solution into a flask holding exactly 100 c. c, 
fill with water to the holding mark, and mix well. 

Soda and Potash. — Evaporate from 1 to 10 litres to 
about 100 c. c. according to the character of the water (5 
litres of Croton water will be enough), acidulate slightly 
with hydrochloric acid, then add saturated solution of 
barium hydrate until the fluid is strongly alkaline, boil, 
filter, and wash well with hot water, to remove chlorides. 
From the filtrate precipitate excess of barium, by adding 
ammonium carbonate as long as it produces a precipitate, 
and boiling. Filter and wash the precipitate of barium 
carbonate with hot water until the washings give no re- 
action for chlorine. Evaporate the filtrate to dryness, and 
burn out the ammonium chloride at low-red heat. Take 
up with water, and repeat the treatment with barium 
hydrate, and ammonium carbonate, to insure the complete 
removal of magnesium, which may have been kept in solu- 
tion by the alkaline chlorides. Finally, evaporate the fil- 
trate to dryness in a weighed dish (preferably of platinum), 
expel any ammonium chloride present, at low red heat ; 
cool and weigh the chlorides of sodium and potassium. 
Dissolve the contents of the dish with water, and determine 
the potassium, as directed in the analysis of potassium 
alum, and calculate the sodium. Consult analysis of feld- 
spar. 

Hardness. — By this is meant the soap-destroying power 
of the water. A degree of hardness means the effect pro- 
duced on a solution of soap by water containing 1 grain of 
calcium carbonate in a gallon. For the determination, 
there will be required a solution of soap, and one of cal- 



HARDNESS. 177 

cium chloride, with which to standardize the solution of 
soap. 

Soap Solution. — To prepare this, dissolve 10 gms. of 
good soda soap (containing about 12 per cent of water), in 1 
litre of 90 per cent alcohol ; filter, and keep the solution 
in a glass-stoppered bottle, and mark it Strong soap solu- 
tion. For use, add to 100 c. c. of the strong solution 100 
c. c. of water, and 33 c. c„ of alcohol, adding the alcohol 
before the water, and shaking gently \ to avoid lathering. 

Calcium Chloride Solution. — To prepare this, dissolve 
1 gm. of calcium carbonate in dilute hydrochloric acid, 
evaporate to dryness on a water-bath, to expel all free acid, 
and dissolve the residue in 1 litre of distilled water. One 
c. c. of this solution will correspond to one mgm. of calcium 
carbonate. Dilute 10 c. c. of the solution to 100 c. c, with 
distilled water, introduce the mixture into a narrow glass- 
stoppered bottle, which holds about 150 c. c, and drop in 
the soap solution from a burette, little by little, intro- 
ducing the stopper into the bottle, and shaking after each 
addition of soap. Continue the operation until a perma- 
nent lather is formed, which will remain unbroken for 5 
minutes. The lather should not be thick and frothy, but 
only a light pellicle covering the surface of the solution. 
When it breaks, the fluid below will appear in patches. 
As the number of milligrammes of calcium carbonate in 
the fluid is known, when the number of c. c. of soap solution 
required to form a permanent lather is also known, a very 
simple calculation will give the number of milligrammes 
that 1 c. c. of the soap solution is equivalent to. 

To determine the hardness of a sample of water, intro- 
duce into a similar bottle 100 c. c. of the water, and treat 
it with soap solution in the same way as directed for stand- 
ardizing the latter. The number of c. c. of soap solution 
required, multiplied by the value of 1 c. c, and this prod- 
uct multiplied by 10, will give the number of milli- 
grammes of calcium carbonate in the litre that the hardness 
of the water is equivalent to. This number of milli- 



178 WATER. 

grammes multiplied by 58,318, and divided by 1,000,000, 
will give the corresponding nnmber of grains of calcium 
carbonate in 1 gallon, or degrees of hardness. The hard- 
ness of water may be due to the presence of carbonates or 
sulphates, or, though rarely, to the presence of free acid. 
If it is desired to determine the ' ' permanent' ' hardness, 
introduce into a flask holding about 250 c. c, 100 c. c. of 
the water, and boil for half an hour, to precipitate the car- 
bonates held in solution by carbonic acid, make the solu- 
tion up to 100 c. c, with distilled water, and determine the 
hardness as before. This is what is called "permanent" 
hardness. The difference between this and the hardness 
of the water, before boiling, is called \ ' temporary' ' hard- 
ness. To avoid much loss by evaporation while boiling, 
it is well to insert into the mouth of the flask a cork, 
through which passes a piece of glass tubing, about 3 feet 
long, which has a small bulb blown in it. By this means 
the steam will condense and run back into the tube. 
The quantity of water tested should not contain more than 
12 milligrammes of calcium carbonate. If it does, take a 
smaller quantity, dilute with distilled water to 100 c. c, 
and proceed as before. 

This determination is valuable, as it will often obviate 
the necessity of an analysis to decide upon the fitness of 
water for manufacturing purposes, and particularly for use 
in steam-boilers. 

Permanganate Test (vid. W. A. Miller, Jour. Lon. 
CJiem. Soc, 1865, XVIII., p. 117).— This test is made to 
determine the amount of oxidizable organic matter in 
water, and is claimed by some able chemists to be equal in 
value to the determination of albuminoid ammonia. Dis- 
solve 0.7875 gm. of crystallized oxalic acid in 1 litre of 
distilled water ; then 1 c. c. of the solution will be equiva- 
lent to one tenth of a milligramme of oxygen, as 0.7875 
gm. of oxalic acid (H 2 C 2 4 .2H 2 0) requires 0.100 gm. of 
oxygen to become carbonic acid (C0 2 ). Then dissolve 0.500 
gm. of potassium permanganate in 1 litre of water, and 



PEKMANGANATE — XESSLEKIZING. 179 

dilute until 1 c. c. of the solution oxidizes 1 c. c. of the 
oxalic acid solution. Then 1 c. c. of the potassium per- 
manganate solution carries one tenth of a milligramme of 
available oxygen. To 200 c. c. of the water add 3 c. c. of 
dilute sulphuric acid, and permanganate solution until the 
color ceases to disappear for three hours. From the num- 
ber of c. c. of permanganate used, calculate the quantity 
of oxygen required to oxidize organic matter. It is 
assumed that the oxygen required, multiplied by 8, is 
equivalent to organic matter. (See Tidy's analysis of 
London water, Reports to Local Government Board on 
Metropolitan Water, 1878.) 

Free and Albuminoid Ammonia. — The determination of 
these requires what is known as ISFessler' s solution ; also a 
solution of ammonium sulphate or chloride for compari- 
son, a strong solution of sodium carbonate, one of potas- 
sium permanganate, and also distilled water free from 
ammonia. (See Water Analysis, Wanklyn & Chapman, 
4th Ed., London, 1876, pp. 20 et seq.) 

Nesslef s Solution. — To prepare this solution, dissolve 
50 gms. of potassium iodide in a small quantity of hot 
water, place the solution on a boiling water-bath, add, 
with frequent agitation, a strong aqueous solution of mer- 
curic chloride (40 gms. of the salt and 300 c. c. of water), 
until the red precipitate just redissolves, filter, &dd to 
the filtrate a strong solution of 200 gms. of potassium 
hydrate, filter, dilute to one litre, add 5 c. c. of a saturated 
solution of mercuric chloride, allow the precipitate formed 
to settle, decant the clear fluid, and keep it for use in a 
tightly corked bottle. 

Ammonium Solution for Comparison. — Dissolve 0.3883 
gm. of ammonium sulphate, or 0.315 gm. of ammonium 
chloride, in 1 litre of water, and 1 c. c. of either solution 
will contain one tenth of a milligramme of ammonia 
(NH 3 ). For use dilute to ten volumes, and then 1 c. c. will 
contain one hundredth of a milligramme of ammonia. 

Sodium Carbonate Solution. — Add 100 gms. of sodium 



180 WATER. 

carbonate to 200 c. c. of distilled water free from ammonia, 
and keep in a well-corked bottle. 

Potassium Permanganate Solution. — Dissolve 200 gms. 
of potassium hydrate and 8 gms. of crystals of potassium 
permanganate in 1 litre of distilled water free from am- 
monia, boil hard for half an hour in a two litre flask, 
to expel ammonia, and keep in a well-corked bottle. 

Distilled Water. — Boil distilled water, after adding a 
little sodium carbonate, in a large flask, until about one 
fourth is evaporated, then distill the remainder from a re- 
tort holding about 1500 c. c, until the distillate gives no 
reaction for ammonia with Nessler solution, testing 50 c. c. 
of the water at a time. When no more ammonia can be 
detected, distill off into a large bottle about 750 c. c, and 
test again, to be sure that the 750 c. c. are free from am- 
monia. Proceed in the same way until enough is pre- 
pared, and keep the pure water in tightly-corked bottles. 

Before using the solutions of sodium carbonate and po- 
tassium permanganate, they should be tested for am- 
monia. Introduce into a retort, holding 1500 c. c, 1 litre 
of water, add 15 c. c. of the solution of sodium carbonate, 
and 50 c. c. of the potassium permanganate solution, and 
distill until the distillate gives no reaction for ammonia. 
Then distill 500 c. c. of the water, which will be free from 
ammonia. Introduce this water into a clean retort, add 
15 c. c. of the solution of sodium carbonate, and distill 
until the distillate ceases to give a color upon the addition 
of Nessler solution, and determine the ammonia as di- 
rected later and note the amount upon the bottle. Then 
add 50 c. c. of the potassium permanganate solution, and 
proceed in the same way, marking the amount of ammonia 
found upon the bottle. The solutions should be tested 
frequently. 

Free Ammonia. — Connect a retort (of capacity of at least 
1 litre) with a good condenser, cleanse by distilling some 
clean water in them, introduce 500 c. c. of the water to be 
tested and 15 c. c. of the Na^CC^ solution ; distill, collect- 



FREE AND ALBUMINOID. 181 

ing the distillate in test cylinders. Meanwhile place in 
other cylinders of the same calibre, amounte of the standard 
NH 3 solution containing respectively 0.01, 0.02, etc., mgm. 
NH 3 , and dilute each up to 50 c. c. When 50 c c. have 
distilled over, add 1.5 c. c. of Nessler solution to each cylin- 
der. Always use the same Nessler solution, and the same 
amounts, and allow it to act as nearly as possible for the 
same length of time. After a few minutes compare the 
tint of the distillate with those of the comparison cylinders, 
and thus estimate the amount of ammonia present therein. 
If the water is likely to contain much ammonia, it will 
be safer to mix the distillate by stirring, take out 10 c. c, 
dilute to 50 c. c, and test as described above. The re- 
maining four fifths of the distillate may be used to confirm 
the results thus obtained. Test each succeeding 50 c. c. 
of the distillate in the same way, and proceed until 50 c. c. 
contain less than 0.01 mgm. NH 8 . The whole amount of 
ammonia thus determined, less that due to the 15 c. c. Na 2 
C0 3 gives free ammonia. 

Albuminoid Ammonia. — When the distillation with 
Na 2 C0 8 fails to show ammonia, add 50 c. c. of the perman- 
ganate solution and distill, testing each successive 50 c. c. 
of the distillate as before, until it contains less than 0.01 
mgm. ]STH 3 . Deduct ammonia due to permanganate, and 
the result is albuminoid ammonia. 

A modification, which avoids corrections for ammonia in 
the reagents, may be stated briefly thus : Distill 200 to 3o0 
c. c. of clean water with 15 c. c. Na.jC0 3 until the distillate 
is free from ammonia ; add 500 c. c. of the water and distill, 
testing the distillates for free ammonia ; add 50 c. c. per- 
manganate solution and again distill clean ; then 500 c. c. of 
the water, and test distillates for total ammonia. The differ- 
ence between free and total gives albuminoid ammonia. 

Nitrates (vid. Gladstone and Tribe, Jour. Lon. 

CJiem. Soc, June, 1873). — Evaporate 2 or 3 litres of the 

water to dryness on a water-bath after adding a small piece 

■ of caustic lime, heat the mass with 5 or 6 c. c. of distilled 



182 WATEK. 

water, and rinse it into a 200 c. c. flask, connected with a 
small Liebig condenser, which is also connected by means 
of a glass tube, with another small flask. The latter flask 
is provided with a doubly-perforated cork, through one 
hole of which passes the tube from the condenser, and 
through the other a bent glass tube connected with a small 
U tube containing a little broken glass, and a few c. c. of 
dilute hydrochloric acid. A little thin sheet zinc (10 or 15 
gms. ) is then plated with copper by immersing it in a concen- 
trated solution of copper sulphate for 15 minutes, and in- 
troduce (after washing it with cold water) into the flask 
with the residue. The liquid in the flask is gradually 
heated to boiling, and distilled for about an hour. The 
distillate and washings of the receiver are then evaporated 
with platinum tetrachloride, and from the spongy plati- 
num the nitric acid calculated. (Compare analysis of am- 
monio-ferric sulphate.) 

Grouping the Constituents Found by Analysis. — It is 
almost impossible to give rules for grouping the constitu- 
ents so as to meet all cases. It will be sufficient to give 
directions for grouping the results of analysis of such 
water as is at all likely to be used for drinking or manu- 
facturing. Combine the sodium with chlorine as sodium 
chloride, and the potassium with sulphuric acid as potas- 
sium sulphate. Should there be any more sodium than 
the chlorine will satisfy, and more sulphuric acid than is 
required by the potassium, combine the excess of sodium 
with sulphuric acid as sodium sulphate, and should 
there be more sodium than the sulphuric acid will satisfy, 
calculate the excess to sodium carbonate. Should there 
be more than enough sulphuric acid to combine with 
sodium and potassium, combine the excess first with cal- 
cium, as calcium sulphate, and any further excess with 
magnesium as magnesium sulphate. If the water contains 
a large amount of chlorine (more than enough to satisfy 
the sodium), and not enough sulphuric acid to satisfy the 
potassium, combine the excess of potassium with chlorine, , 



CALCULATION OF KESI7LTS. 



183 



and if there be any chlorine still left, combine it first with 
magnesium, and then, if there be more than enough to 
saturate the magnesium, combine the excess with calcium. 
Calculate all calcium and magnesium not combined with 
chlorine and sulphuric acid to carbonates. 

The following table may be found of use in the analysis 
of mineral and potable waters for the calculation of the 
number of grains in the U. S. gallon of 231 cubic inches, 
the number of milligrammes per litre having been found. 
The number of grains in the gallon has been taken as 
58,318, which is believed to be the most correct figure, 
though authorities on the subject differ slightly from one 
another, e. g., the U. S. Dispensatory gives 58,328.886, or 
nearly 11 grains more. Either of these results gives about 
133.3 avoirdupois ounces in the gallon. 

Table showing the number of grains in the U. S. gallon of 231 cubic inches, corresponding 
to the number of milligrammes in one litre, by E. Waller, A. M., E.M. 



Mgs. 


to 1 Litre = 


Mas. 


to 1 Litre = 


Mgs. 


to 1 Litre = 


Mgs. tc 


1 Litre = 


Grs. 


toU. S. Gal. 


Grs. 


to U. S. Gal. 


Grs. 


to U. S. Gal. 


Grs. to 


U. S. Gal. 


1. 


...0.058318 


26. 


...1.516268 


51. 


. . .2.974218 


76.. 


. .4.432168 


2. 


..0.116636 


27. 


. . .1.574586 


52. 


. . .3.032536 


77.. 


. .4.490486 


3. 


...0.174954 


28. 


. . .1.632904 


53. 


. . .3.090854 


78.. 


. .4.548804 


4. 


. . .0.233272 


1 29. 


. . .1.691222 


54. 


...3.149172 


79.. 


. .4.607122 


5. 


...0.291590 


i 30. 


...1.749540 


55. 


...3.207490 


80.. 


. .4.665440 


6. 


. . .0. 34990 s * 


31. 


...1.807858 


56. 


. . .3.265808 


81.. 


. .4.723758 


7. 


. . .0.408226 


32. 


...1.866176 


57. 


. . .3.324126 


82.. 


. .4.782076 


8. 


. . .0,468544 


33. 


...1.924494 


58. 


. . .3.382444 


83.. 


. .4.840394 


9. 


. . .0.524862 


34. 


...1.982812 


59. 


. . .3.440762 


84.. 


. .4.898712 


10. 


. . .0.583180 


35. 


. . .2.041130 


60. 


. . .3.499080 


85.. 


. .4.957030 


11. 


. . .0.641498 


36. 


. . .2.099448 


61. 


. . .3.557398 


86.. 


. .5.015348 


12 


...0.699816 


37. 


. . .2.157766 


62. 


. . .3.615716 


87.. 


. .5.073666 


13. 


...0.758134 


38. 


...2.216084 


63. 


. .3.674034 


88.. 


. .5.131984 


14. 


. . .0.816452 


39. 


. . .2.274502 


64. 


. .3.732352 


89.. 


..5.190302 


15. 


. . .0.874770 


40. 


. . .2.332720 


65. 


. .3.790670 


90.. 


. .5.248620 


16. 


...0.933088 


41. 


. . .2.391038 


66. 


. .3.848988 


91.. 


.5.306938 


17. 


. . .0.991406 


42. 


. .2.449356 


67. 


. .3.907306 


92.. 


.5.365256 


18. 


...1.049724 


43. 


. .2.507674 


68. 


. .3.965624 


93.. 


.5.423574 


19. 


...1.108042 


44. 


. .2.565992 


69. 


. .4.023942 


94.. 


.5.481892 


20. 


...1.166360 


45. 


. .2.624310 


70. 


. .4.082260 


95.. 


.5.540210 


21. 


...1.224678 


46. 


. .2.682618 


71 


. .4.140578 


96.. 


.5.598528 


22. 


. .1.282996 


47. 


. .2.740946 


72. 


. .4.198896 


97.. 


.5.656846 


23. 


..1.341314 


48. 


..2.799264 


73. 


. .4.257214 


98.. 


.5.715164 


24. 


...1.399632 


49. 


. .2.857582 1 


74. 


. .4.315532 


99.. 


.5.773482 


25. 


...1.457950 


50. 


. .2.915900 I 


75. 


. .4.373850 


100.. 


.5.831800 



CHAPTER XXXI. 



MINERAL WATER. 



The term ''mineral" is usually applied to water possess- 
ing medicinal properties, or an unusual amount of 
mineral matter. It is not proposed here to discuss the 
subject of mineral water, but simply to give methods of 
analysis of two leading varieties — alkaline carbonated 
water and sulphur water, that of Saratoga being an illus- 
tration of the former, and that of Chittenango, New York, 
an illustration of the latter. For more information on the 
subject, the student is referred to Fres., Quant. Anal., 
§206, et seq., and the writers quoted by him, and also to 
Hunt' s Chem. and Geolog. Essays, and his papers in Am. 
Jour. Sci. and Arts, 1865. 

Saratoga Water. — The method given here has been fol- 
lowed for a long time in the Columbia College School of 
Mines, having originated in the private laboratory of Dr. 
C. F. Chandler. The constituents provided foi are 
potash, soda, lithia, lime, magnesia, strontia, baryta, 
oxide of iron, oxide of maganese, alumina, chlorine, 
bromine, iodine, fluorine, sulphuric acid, phosphoric acid, 
boracic acid, carbonic acid, and silica. 

Total Solids. — Evaporate in a weighed platinum dish 
from 200 to 500 c. c. of the water, on a water-bath, and 
dry thoroughly in an air-bath at 130° C. The weight of 
solid residue gives a control of the analysis. Fresenius, 
in his Quant. Anal., § 213, says that " a more exact con- 
trol is attainable as follows : By treating the residue, on 
evaporation, with sulphuric acid, and comparing the re- 
sidue of the sulphates (the iron is present as sesquioxide) 
with the sum of the fixed alkalies, alkaline earths, and 
manganese expressed as sulphates, plus the sesquioxide oJf 
iron, the silicic acid, and the phosphoric acid (as HPO3)/ 1 



IRON, LIME, ETC. — SODIUM CARBONATE. 185 

Oxide of Iron, Alumina, Lime, Magnesia, and Silica. 
—Acidulate 1 litre, or more, in very weak waters, with 
hydrochloric acid, evaporate to dryness, take np with hy- 
drochloric acid and water, filter out the silica, and weigh 
it. Then determine the silica by loss, after treating with 
sulphuric acid and ammonium iiuoride. Should there be 
any residue, fuse it with a little sodium carbonate, digest 
with water, filter out and wash the residue insoluble in 
water, dissolve it in hydrochloric acid, ard examine the 
solution with the spectroscope. Should baryta or strontia 
be present in appreciable quantity, determine them. The 
residue will probably be only ferric oxide, which is to be 
brought into solution, and added to the filtrate from the 
silica. Treat the filtrate with ammonia, filter out the pre- 
cipitate of ferric oxide and alumina, dissolve it in hydro- 
chloric acid, and reprecipitate with ammonia, and deter- 
mine the ferric oxide and alumina together. In the fil- 
trates, determine the lime and magnesia, as in the analysis 
of limestone. 

Sulphuric Acid. — Acidulate 1 litre of the water with 
hydrochloric acid, evaporate to small volume in a porce- 
lain dish, and deternine the sulphuric acid as in analysis 
of magnesium sulphate. 

Sodium Carbonate. — Evaporate 1 litre of the water to 
dryness, digest the residue with boiling water, filter, and 
wash until the washings give no alkaline reaction with 
litmus paper. Carbonates of sodium and lithium go into 
solution. To the filtrate add, in slight excess, a mixture 
of calcium chloride and ammonia (prepared by dis- 
solving 60 gms. of calcium chloride in 250 c. c. of water, 
adding to the solution 100 c. c. of ammonia, filtering, add- 
ing 100 c. c. more ammonia, and diluting to 500 c. a). 
Reaction will take place between the calcium chloride and 
the carbonates of sodium and lithium in the water, by 
which calcium carbonate will be precipitated, and the 
chlorine unite with the sodium and lithium. Filter out 
the calcium carbonate, and wash it repeatedly with water 



186 MINERAL WATER. 

until the chlorides are removed. Then dissolve the pre- 
cipitate through the filter with hydrochloric acid, precipi- 
tate the calcium as oxalate, and determine it as sulphate, 
as in analysis of calcite. Estimate the corresponding 
amount of acid sodium carbonate. 

As this method of analysis, intended strictly to meet the 
case of Saratoga water, is applicable in most points to the 
analysis of other alkaline carbonated waters, it is proper to 
mention that in some cases it must be modified. Sodium 
carbonate may exist in presence of excess of carbonic acid 
and of magnesium carbonate, before evaporating the 
water, but by evaporating, calcium carbonate, magnesium 
sulphate and sodium sulphate will be formed. (Hunt.) 
In such a case it is better to determine the alkalies in ex- 
cess over what is required to combine with chlorine and 
sulphuric acid, and calculate the sodium carbonate. In 
such cases, determine the sodium, as directed in analysis 
of fresh water. 

Potas7i. — Evaporate 1 litre of the water nearly to dry- 
ness in a silver or platinum dish, filter, and wash with 
boiling water until the washings give no alkaline reaction 
with litmus. If the water is strongly saline, evaporate 
one tenth of the solution, on a water-bath, to the consist- 
ency of syrup, after acidulating with hydrochloric acid, 
and adding an amount of solution of platinum tetra- 
chloride containing platinum tetrachloride equal in weight 
to four times that of the chlorides of the alkalies present, 
and determine the potash as directed in the analysis of 
potassium alum. 

Should there be any sodium salt unconverted, or sodium 
platino- chloride difficult to dissolve in the alcohol, filter, 
wash on the filter with hot water, into another beaker, 
until only yellow potassium platino-chloride is left, evap- 
orate the filtrate as before, after adding more platinum 
tetrachloride, filter, and combine the precipitates of pure 
potassium platino-chloride, and determine the potassium. 

In water containing soluble salts of calcium, partic- 



CHLORINE — CARBONIC ACID. 137 

ularly calcium sulphate, some may remain with the platino- 
chloride undissolved by the alcohol, and be found with the 
spongy platinum after ignition. In such a case, the resid 
ual platinum may be purified by boiling it with hydro- 
chloric acid and water, filtering, and washing thoroughly. 
The better plan, however, in the case of water of such 
a character, is to determine the potassium as in the analy- 
sis of feldspar. 

Chlorine. — Determine the chlorine in 25 c. c. of the 
water, after diluting it with about 100 c. c. of distilled 
water, by a standard solution of silver nitrate, as directed 
in the analysis of fresh water. In water containing less 
chlorine than those of Saratoga, a larger amount must be 
used for the determination, evaporating, if necessary. The 
chlorine may be determined gravimetrically, as in the 
analysis of barium chloride. It must be borne in mind 
that iodine and bromine act similarly to chlorine on the 
silver solution, and that a proper correction must be made 
on account of their presence. 

Carbonic Acid. — Introduce into each of several bottles, 
of a capacity of about 300 c. c. , and provided with tightly 
fitting glass-stoppers, exactly 50 c. c. of a solution of cal- 
cium chloride and ammonia, prepared as directed in the 
paragraph on sodium carbonate, and introduce into each 
one 200 c. c. of the water, at the spring, before the free 
carbonic acid has had time to escape, insert the stoppers 
slightly greased with pure tallow, and secure them with 
pieces of cloth firmly tied to the necks of the bottles. 
Afterward, in the laboratory, remove the stopper from a 
bottle, cleanse it, as well as the neck of the bottle, from 
all grease, drop it again loosely into the neck, place the 
bottle in water, and boil until violent effervescence ceases. 
Then filter out the calcium carbonate, rinse the bottle 
thoroughly with water, pouring the washings on the same 
filter, and keep the bottle for further treatment. Wash 
the calcium carbonate on the filter as long as the wash- 
water gives any reaction with ammonium oxalate. This 



188 MINEEAL WATEE. 

washing should be done rapidly, to avoid the formation of 
calcium carbonate by the carbonic acid in the atmosphere. 
Dissolve the calcium carbonate adhering to the bottle with 
a little hydrochloric acid, and wash into a beaker. Then 
perforate the filter with a rod, wash the precipitate through 
it into the same beaker, cleansing the filter with hydro- 
chloric acid, boil, to expel free carbonic acid, determine 
the calcium as in analysis of calcite, and calculate the car- 
bonic acid. Confirm the results by treating another 
bottle in the same way. 

Treatment for Substances in Minute Quantities. — If the 
water is not alkaline to litmus without boiling, it is better 
to add sodium carbonate until the water has a slight 
alkaline reaction, as otherwise iodine and bromine may be 
lost by evaporation. Evaporate from 10 to 20 gallons of 
the water to dryness in an even number of porcelain 
dishes, introducing the same quantity of water into each, 
by which means the weighing and dividing the salts 
soluble in water may be avoided, as will be seen later. 
Complete dryness is not necessary. Treat the residues 
with hot water, boil, decant through two filters, repeat 
the treatment several times, and finally throw the residues 
on the filters, and wash until no trace of lithium can be 
detected. If it is found to be difficult to wash out the 
lithium from the residues, it is well to wash moderately, 
until no bromine can be detected in the washings, and 
determine the lithium in the residues. 

There will be — 1st. Two Insoluble Residues. 2d. Two 
Solutions. 

Treatment of the Insoluble Residues. 

First Case. — If lithium be not present in the water, or 
be completely removed by hot water, dissolve the residues 
in hydrochloric acid, combine the solutions, evaporate to 
dryness, add a little hydrochloric acid to the dry mass, 
heat, dilute with water, and filter out the residual silica, 
which may contain sulphates of barium and strontium. 
Expel the silica with ammonium fluoride and sulphuric 



IKON, ETC. — BARIUM AND STRONTIUM. 189 

acid, fuse the residue with sodium carbonate, digest with 
water, throw the mass on a filter, wash out alkaline sul- 
phates, dissolve the carbonates left on the filter with hy- 
drochloric acid, and determine the barium and strontium in 
the manner directed later. Divide the filtrate from the 
silica into 3 equal parts. 

Firsts for phosphoric acid. 

Second, for iron and manganese. 

Third, for barium and strontium. 

Treatment of the Part for Phosphoric Acid. — Expel 
the hydrochloric acid, and convert chlorides into nitrates 
by evaporation with excess of nitric acid, diluting, adding 
ammonium molybdate, and proceeding as directed in 
analysis of iron ore. 

Treatment of the Part for Iron and Manganese. — 
Precipitate the iron as basic acetate, filter, dissolve the 
precipitate with hydrochloric acid, and precipitate again, 
filter, wash with hot water, combine the filtrates, evaporate 
to small volume, and determine the small amount of man- 
ganese, frequently found in water as manganous oxide, as 
directed in analysis of manganese ore. Bring the basic 
acetate in sulphuric acid solution, and determine the iron 
by titration with solution of potassium permanganate, as 
in analysis of ammonio-ferric sulphate. 

Treatment of the Part for Barium and Strontium. — 
Dilute the solution with water, add dilute sulphuric acid, 
and boil. Enough acid should be added to precipitate a 
little calcium, or some strontium may remain in solution. 
At the same time care must be taken not to precipitate too 
much calcium, or it will be difficult to wash, and strontium 
may be lost in the alcohol, which is rarely, if ever, abso- 
lute. The precipitate consisting of sulphates of barium 
strontium and calcium should be treated with a strong so- 
lution of ammonium carbonate, which will convert the 
oxides of calcium and strontium into carbonates, while 
fhe barium sulphate will be unaffected. The carbonates 
are then dissolved away from the barium sulphate on the 



190 MINERAL WATER. 

filter, with cold dilute hydrochloric acid, the barium sul- 
phate washed with water, dried, ignited, and weighed, 
and the barium calculated. (H. Rose, Pogg. Annal., 
XCV., 286, quoted by Fres., Quant. Anal, § 154, 3, p. 
347.) The hydrochloric acid solution is evaporated to dry- 
ness with excess of nitric acid, to convert the chlorides 
into nitrates, and the nitrate of calcium dissolved out with 
a mixture of equal parts of alcohol and ether. (H. Rose, 
p. 95.) 

The residual strontium nitrate is dissolved in water, and 
the strontium determined as sulphate. (See Fres., Quant. 
Anal., § 72, p. 107.) All the precipitates should be tested 
by the spectroscope. 

Second Case. — If lithium be present, and be not com- 
pletely removed by hot water, which will be almost always 
the case if there be much in the water, divide the hydro- 
chloric acid solution of the residues insoluble in hot water, 
into 4 equal parts (instead of 3), in one of which the 
lithium is to be determined, while the other 3 are to be 
treated as directed in the fir st case. 

For the determination of the lithium, evaporate the solu- 
tion to dryness on a water-bath, transfer the residue to a 
flask, and proceed as directed later for the determination 
of lithium in the water solution. Also consult Fres., 
Quant. Anal., §209, 7, 4th London Ed., 1865. 

Treatment of Water Solutions. — There will be two, if 
the plan suggested before, of evaporating the water in 
separate portions has been followed. Evaporate each to 
dryness, and appropriate one to the determination of 
lithium, and the other to the determination of iodine and 
bromine. It is to be remembered that in waters contain- 
ing a large amount of chlorine, and also barium and 
strontium, the latter, or at least a portion, may be found 
in the water solution, instead of the insoluble residue, and 
that in such a case, a portion of the water solution must 
be taken for their determination. 
Lithium and Boracic Acid. — When the solution in 



LITHIUM — IODINE, BROMINE, ETC. 191 

which the lithium is to be determined has been evaporated 
to very small volume, pour about 1 c. c. of it into a watch- 
glass, acidulate it with hydrochloric acid, and test it with 
turmeric paper for boracic acid, traces of which are gen- 
erally found in water of Saratoga. Wash back the fluid 
used for the test, and continue the evaporation to dryness. 
Then moisten the dry residue with hydrochloric acid, 
evaporate again to dryness on a water-bath ; dry heat 
must not be used, as the lithium chloride is very easily 
decomposed by heat, being converted into oxide which is 
insoluble in absolute alcohol. After evaporating the ex- 
cess of hydrochloric acid, transfer the dry residue to a 
capacious flask, agitate well with absolute alcohol, decant 
through a filter, repeat until the residue gives no reaction 
for lithium in the spectroscope, evaporate the alcohol on a 
water-bath, and dissolve the residue in water. 

As magnesium carbonate is not entirely insoluble in 
water in presence of chlorides, some magnesium will be 
found in the solution resulting from the treatment of the 
residue of the original evaporation, and must be removed 
before determining the lithium as phosphate. To effect 
the removal of magnesium, make the solution alkaline 
with the barium hydrate, filter, and from the filtrate pre- 
cipitate the excess of barium with ammonium carbonate, 
add to the filtrate about 6 gms. of pure hydro-disodium 
phosphate, enough pure sodium hydrate to keep the reac- 
tion alkaline, and evaporate the mixture to dryness ; pour 
water over the residue in sufficient quantity to dissolve 
the soluble salts with the aid of a gentle heat, add an equal 
volume of ammonia, digest at a gentle heat, filter after 12 
hours, and wash the precipitate with a mixture of equal 
volumes of water and ammonia. Evaporate the filtrate 
and first washings to dryness, and treat the residue in the 
same way as before. If some more lithium phosphate is 
thereby obtained, add this to the principal quantity. (See 
Pres., Quant. Anal., § 100, p. 164.) 

Iodine, Bromine, and Nitric Acid. — Evaporate thesolu- 



192 MINERAL WATER. 

tion, in which these are to be determined, to dryness, 
transfer the dry residue to a capacious flask, and boil on 
a water-bath repeatedly, with 85 per cent alcohol, de- 
canting on a filter each time, until the residue gives no re- 
action for bromine, when treated with fuming nitric acid 
and carbon disulphide. Evaporate the alcohol on a water- 
bath, and when the alcohol is expelled, test a little of the 
substance for nitric acid. To determine nitric acid, 
evaporate a separate portion of the water, and proceed as 
directed in the analysis of fresh water. After expelling 
the alcohol, wash the residue into a platinum dish, add 
about 5 times its weight of sodium carbonate, dry, and 
fuse. This is done to decompose any organic matter which 
may be present, either from having been held in the water 
originally or extracted from the vessels in which the water 
was collected. Organic matter must be removed, or it 
will, upon the addition of palladium chloride, cause a pre- 
cipitate of palladium oxide with the iodide, and thereby 
vitiate the determination. Dissolve the fused mass in 
water, acidulate slightly with hydrochloric acid, add 
slight excess of palladium chloride, allow the whole to 
stand for 24 hours in a warm place, filter out the pal- 
ladium iodide, wash with warm water, dry, ignite, and 
from the metallic palladium calculate the iodine. 

To the filtrate from the palladium iodide add sodium 
carbonate in excess, evaporate to dryness, digest the dry 
residue with boiling absolute alcohol, decanting on a 
filter, and repeating the treatment until the residue gives 
no reaction for bromine, when tested with fuming nitric 
acid and carbon disulphide. When the bromine is all ex- 
tracted from the residue, evaporate the alcoholic solution 
to dryness, after adding a little sodium hydrate, dissolve 
the dry residue in water, add excess of silver nitrate, 
filter out the precipitate of bromide and chloride of silver, 
wash with hot water, dry the precipitate, fuse it in a 
weighed porcelain crucible, and weigh. Then pour water 
on the fused mass in the crucible, add a little hydrochloric 



BROMINE — CALCULATION. 193 

acid and a fragment of zinc. In 24 hours, the silver will be 
completely reduced. The silver is then rubbed to powder, 
boiled with water containing a little hydrochloric acid, 
washed with pure water, gently ignited, and weighed. 
The difference between the atomic weights of chlorine and 
bromine is to the atomic weight of bromine as the differ- 
ence between the amount of chloride and bromide of silver 
employed, and the amount of chloride which the reduced 
silver ought to yield is to the amount of bromine present. 
(See Wohler's Mineral Analysis, p. 213; and Fres., 
Quant. Anal., § 169, p. 412.) 

As silver chloride is not absolutely insoluble in hydro- 
chloric acid, it is well to test the fluid, after treating the 
reduced silver with hydrochloric acid to remove any traces 
of zinc remaining with the silver, and if any silver chloride 
be recovered, add the weight of it to that calculated from 
the reduced silver, before making the calculation as direct- 
ed above. On the other hand, as a slight amount of chlo- 
ride may escape reduction, it is well to treat the reduced 
silver with a little ammonia, filter, wash, ignite, and weigh 
the silver again. The loss will be silver chloride. Estimate 
the chlorine in it, and substract it from the first weight. 
After making these corrections, calculate the bromine. 

Calculation of the Analysis. — The sulphuric acid is 
combined with potassium to form sulphate. 

The potassium unsatisfied by sulphuric acid is combined 
with chlorine to form potassium chloride. 

The chlorine not required by potassium is combined with 
sodium to form sodium chloride. 

The bromine, iodine, phosphoric acid, boracic acid, and 
nitric acid are combined with sodium, to form bromide, 
iodide, phosphate, biborate, and nitrate. 

The sodium bicarbonate is determined directly. 

The sodium is not determined, but is assumed as the sum 
of all required to combine with chlorine, bromine, iodine, 
phosphoric acid, boracic acid, nitric acid, and carbonic acid. 

The lithium, magnesium, calcium, less that for fluorine, 



194 



MINERAL WATER. 



strontium, barium, iron, and manganese, are combined 
with carbonic acid tc form bicarbonate. 

The fluorine is calculated to calcium fluoride. 

The alumina, silica, and organic matter are reported as 
such. 

Sulphur Waters. — The constituents of these waters are 
very similar to those found in most spring waters, with 
the exception of the sulphur compounds, as will be seen 
by the subjoined report of analyses of the waters of Chit- 
tenango, Madison Co., "N. Y., taken from a lecture of Dr. 
C. F. Chandler, published in Am. Chem., December, 1871. 

ANALYSIS OF SULPHUR WATERS. 



In One U. S. Gallon of 231 Cubic 


Chittenangc 


>, Madison County, N. Y. 


Florida 

Spring, 

Montgom'ry 

Co., N. Y. 


Inches. 


White Sul- 
phur Sp'g. 


Cave Spring. 


Magnesia 
Spring. 


Hydrosulphate of sodium, 
NaHS 


Grains. 
0.117 

oiii 

81.420 

Trace. 

1.953 

22. 017 
0.078 
0.156 
1.037 

Trace. 
0.082 
0.288 

Trace. 


Grains. 
0.3S6 
1.123 

106'. 126 
Trace. 

7.589 
0.257 

23.973 
0.156 
0.233 
1.569 

Trace. 
0.222 
0.519 


Grains. 
0.757 
0.929 

115.085 
Trace. 

12.718 
0.020 

20*. 779 
0.325 
0.333 
1.833 

Trace. 

Trace. 
0.577 


Grains. 
2.008 


Hydrosulphate of calcium Ca 
(HS)o 




Sulphate of potassa 

Sulphate of soda 


1.390 


Sulphate of lime 




Sulphate of strontia 

Sulphate of magnesia 


.... 


Hyposulphite of soda 


0.711 


Bicarbonate of soda, NaHC0 3 . 


22.143 
8.317 


Bicarbonate of magnesia 

Bicarbonate of iron 

Chloride of potassium 


6.972 

5*. 880 








Trace. 


Silica 


0.79a 


Sulphur (in suspension) 

Sulphide of iron (in suspension) 


0'.176 


Total solid contents per gallon 

Total sulphur in the metallic 

sulphides and sulphuretted 


107.359 
0.339 


142.113 
1.397 


153.356 
2.400 


43.390 
1.9165 






CUBIC INCFI 


:s OF GAS 


PER GALLO 


N. 




Sulphuretted hydrogen gas 


0.884 
20.480 


2.754 

15.934 


5.623 
19.456 


3.765 
32.169 . 




— • 



THE FOLLOWING STATEMENT OF ANALYSES OF SARATOGA WATER IS TAKEN FEOM A LECTURE ON WATER, DELIVERED BY DR. C. F. CHAND. 
LER, AND PUBLISHED IN THE AMER. CHEMIST, DECEMBER, 1871. 

ANALYSES OF SOME OP THE SPRINGS AND ARTESIAN WELLS OP SARATOGA COUNTY, N. Y. 





In Saratoga. 


In Ballston. 


compounds as they exist in 
Solution in the Waters. 


Star 
Spring. 


High 

Rock 
Spring. 


Seltzer 
SpriDg. 


Pavilion 
Spring. 


United 

States 
Spring. 


Hathorn 
Spring. 


Crystal 
Spring. 


Congress 
Spring. 


Geyser 

s wei'r g 


Vichy. 


Emnire Glacier 


Ballston 

Artesian 
Lithia Well 


Franklin 1 Conde 
Artesian Deniimiuu 
Well. Well. 


Chloride of sodium 


398361 

9 -095 

126 

1 586 
12-002 
01 ill 2 

124-459 

Trace. 
0-096 
1-213 
5-400 

Trace. 

Trace. 

Trace. 

Trace. 


390-127 
8-974 
0-731 
0086 
Trace . 
1-967 

54-924 
131-739 

Trace. 
0494 
1-478 
1-608 

Trace. 

Trace. 
1-223 
2-260 


134-291 
1-335 

0-031 


459-903 
7 660 
0-987 
0-073 


141-872 
8-624 
0-844 
047 


509-968 
9 597 
1-534 
0-198 


328-468 
8-327 
0-414 
0-066 
Trace. 
4-326 
10-064 
75 101 
101-881 

Vfle 

2-038 
2158 

Trace'. 
0-305 
3213 


400-444 
8-049 
8-559 
0-138 
Trace. 
4-761 
10-775 
121-757 
143-399 

0-92S 
0-340 
0-889 








750-030 

33-276 
3-643 
0-124 

Trace. 
7-750 

11-928 
180-602 
238-156 
0-867 
3-881 
1-581 
0-520 
050 

Trace. 
0-077 
0-761 

Trace. 




Chloride of potassium 

Bromide of sodium 

Iodide of sodium 


24 034 14-113 
2-212 0990 
0-248 Trace. 


8-733 
1307 
0039 

Trace. 
2-605 

17-010 
109-0S5 

90-703 

1-818 
026 

Trace. 
324 
2 653 

Trace. 


4292 40-440 
0-266 3-579 
0606 0-234 


33-9311 

0-235 
Trace. 
6-777 
94-604 
177-808 
2,12 332 
0-002 
1-231 
1-009 
0-762 


9232 
2-368 
0-225 

Trace. 

10-514 

34-400 
158-348 
178-484 
0-189 
4-739 
2-296 

Trace. 


Bicarbonate of lithia 

Bicarbonate of soda 

Bicarbonate of magnesia 

Bicarbonate of lime 

;: arbonate of sti-ontia 

Bicarbonate of baiyta 

Bicarbonate of iron 

: '.nl| .I-iuli- <»l 1" .l.'s;;;i 


0-8991 9-486 
29428 3-764 
40-339 76-207 
89-869 120-169 

Trace. Trace. 

Trace. 1 0-875 
1-703 2-570 
0-557 2-032 

Trace.! 0-007 

Trace. Ti-aci-. 

2-561 3-155 
Trace. 1 Trace. 


4847 11-447 

^4- i .-■"-'** 

93-Vui riii-o-o; 

0-018: Trace. 

0-909! 1-737 

0-714 1-128 
Trace. ! Trace. 

0-016, 0-006 


7-004 
71-232 
149-343 
170-393 
0-425 
2-014 
0-979 
318 


1-760 

82-873 
41-503 
95-522 
Trace. 

593, 

S £ = - 

Trace. 

Trace. 
0-473 
0-758 

Trace. 


2-080 
9022 
42-953 
109-056 
Trace. 
0-070 
0-793 

0023 
Trace. 
0-418 
1-458 
Trace. 


6-247 
17-624 
193-972 
227-071) 
0-082 
2-083 
0.647 
0-252 

o-oio 

Trace. 
0-458 
0099 

Trace. 




Trace.' Trace. 
Trace. I Trace. 
0-840] 0-665 
Trace. 1 Trace. 




Alumina 

Silica 


0094 
3-184 
Trace. 


0-131 
1-260 
Trace. 


0263 0-395 
0-735 ; 1 . 02e 






Total per U. S. gal., 231 cu. in. 


617-367 


630-500 


302-017 687-275 


331-837 


888-403J 537-155 


700-895 991-546 


367-326 


701-174 


680-430 


1,195-582 


1,233-240 


1,184-368 1,047-700 




407650 

1-0091 


4 09-458 
1-0092 
52° P. 


3-; 4 1180 332-458 


24 .V 734 
1-0035 








383-071 


384 2101 


344-009 


405-458 


1 426-114 
1-0159 
j 52° F. 


460-066 

10135 
52° F. 


, 




1-0115 


1-OO60 
50° P. 


1-096 
52° F. 






Temperature 


50° F. 




46° F. 


50° P. 


48° P. 
























BASES AND ACIDS, AS ACTUALLY FOUND IN THE ANALYSES, UNCOMBINED. 












7-496 

160-239 
0-163 

43024 

Trace. 
0-056 

11.-992 
0491 

Trace. 

246-357 

443 

0-106, 

Trace.! 
2-483 

Trace. 

Trace. 

56-606 

56-606 
1-283 

Trace. 

33160 
0-496 
0-187 
1-206, 


5-419 

'ii-i-o-.' 

45-540 

Trace. 
0-292 

15-048 
0-598 
1 -223 
241017 
0-568 
0072 

Trace. 
0-739 

Trace. 

62-555 

62555 

2-200 
Trace. 
25 -.591 
148 
0-232 


61-003 
• 0-093 
31-066 
Trace. 
Trace. 

J 1-051 

0-374 

82128 

0-026 
Trace. 

0-256 
Trace. 
Trace. 

44-984 

44-984 
2-561 

Trace. 

18-405 
0-051 
0-105 
2-803 


4-931 

183(181 

0-976 
41-540 
Trace. 

0-517 

20 -8! 15 
1-040 
0-329 
282-723 
0-767 
0-060 

0934 
0-004 
Trace. 

60-461 

60-461 
3155 

Trace. 

24-736 
0-187 
1-116 
358 

o-ooi 


4-515 

57-259 
0-499 

32 189 
0-009 
0-537 

19-908 
0-289 
0094 

90-201 
0-656 
0-039 

Trace. 

Trace. 
0-008 

Trace. 

50380 

3184 
Trace. 
20-613 


5-024 

202-058 
1-179 

58-989 

Trace. 
1-026 

48-340 
0-456 
0131 
314(137 
1-188 
0-166 

Trace. 

Trace. 
0-003 

Trace. 

104-928 

104-928 

Trace. 
42-929 


5-326 

132-006 

445 

35-218 

Trace. 
0-429 

20-592 
824 
0-305 
203-292 
322 
0-055 

Trace. 
0-992 
0-004 

Trace. 

54-984 

54-984 
3-213 

Trace. 

22-4:>i; 
0199 
0-509 
0959 


4 611 

102-321 
0-490 

49-56! 

Trace. 
0-549 

33-358 

Trace. 

2 10-834 
0-045 
0-117 

Trace. 
0-409 
0-008 

Trace. 

80-249 

80-249 
0-840 

Trace. 

33-828 
082 
0-563 
1-024 
0-002 


13-039 

251-031 
0-720 

58901 
211 
1190 

40-915 
396 

Trace. 

352-825 
1-718 
0-208 

Trace. 
0-146 

Trace. 

Trace. 

112-880 

112 880 
0-665 

Trace. 

46-183 
029 
0824 


7-400 
0181 

350 
11-370 

0-021 

0-473 
84-807 

0-769 
Trace. 
Trace. 
Trace. 

Trace. 

60-840 

60-839 
0-758 

Trace. 

24-891 



0-207 
7-893 


5-487 
185- 151 

0-268 
33-428 
Trace. 

1-007 

30-1151 

o-ioo 

0-324 

282-175 

1-015 

033 

Trace. 
0-835 
0013 

Trace. 

64-974 

64-974 

2-653 
Trace. 

0-302 
1-620 
0-003 


3-492 

302-9 1: 
214 
37 906 


21-312 
281758 
0643 
78-493 
0-040 
1-230 
53-142 
263 
0-458 
445-392 
2-780 
0198 


17-653 

299-005 

0-798 

82326 
0-430 
2 292 

49-480 

0-077 

470-097 

2829 

0-104 

Trace. 
0-239 
0-025 

Trace. 

125-973 

125973 
0-761 

Trace. 

51-543 
0-048 
0911 
1-136 
006 


18-104 

286 221 

0-608 

69-942 
0001 
0-727 

48-731 
0-651 
0-203 
416-278 
3-623 
0-197 

0-350 
0000 
Trace. 

136133 

136133 
0-735 
Trace. 

'o-070 
0-797 
9-011 

o-ooi 


4833 




Lithium 


1-082 








0-041 
11-768 
321 
0-418 
308-357 
0-107 
0-513 




Magnesia 

Protoxide of iron 

Chlorine 


43 383 
0-929 
0-395 

390-090 


Iodine 


0189 




••"i-272 
011 


0-115 
005 




l'linsplH»ncacidtP 2 B ) 




Oarboiiic *>cid (C0 2 ) in carbon- 
ates 

1 Carbonic acid (CO a )for bicar- 


45-972 

45-972 
1-458 

18-720 

0-215 

0-005 


127-298 

127-298 
0-699 

"' 52-077 
0023 
0-735 
1-678 

o-ooi 


110-019 


Silica 

Organic matter 

Wat i-r in bicarlionates 

Oxygen in K 2 S0 4 

< .xvrmi in Lit ICO, 


1026 
Trace. 
45013 


0-570 
444 
0-002 


1-347 
0-408 

o-ooi 


1-237 
3-277 




Trace. 










Total per U. S. gal., 231 cu. in. 


(i 17-307 


630-500 


302-007 


687-275 


331-837 


888-403 


537-155 


700-895 


901-546 


307-320 


701 174 


680 430 


1,165-582 


1,233246 


1,184-368 


1,047-700 


Total residue by evaporation. 


537-600 


542-350 


238-970 


602-080 


260840 


740-550 


459070 


588-818 


S32-4 83 


281-595 


609-613 








1,055-730 


992540 


892-670 



;ime to time 



SULPHUR COMPOUNDS IN WATER. 195 

' •' The analyses were made in the Editor' s laboratory, 
with the assistance of W. H. Chandler and F. A. Cairns." 

The evaporation of large quantities of the water, and 
the determinations of the ordinary constituents are made 
in the way directed in analysis of Saratoga water. 

Sulphur Compounds. — The following extract from the 
Cliem. News, American Supplement, April, 1870, gives 
the method of determining the sulphur compounds : k ' The 
method employed for determining the sulphur compounds 
was a modification of the one employed by Simmler in the 
analysis of the Stachelberg water, the account of which 
was published in Erdmanrt s Journal, Yol. LXX. The 
alterations introduced lessen to a great extent the amount 
of analytical work to be done at the spring. The follow- 
ing brief statement may prove of interest : 

"1. In a glass-stoppered bottle, to one litre of water was 
added an excess of neutral solution of nitrate of silver. 

" 2. To another litre was added an excess of a solution of 
chloride of cadmium. 

" 3. Through a third litre pure hydrogen was transmitted 
until the gas, after passing through the water, no longer 
decolorized a dilute solution of iodide of starch. An ex- 
cess of a solution of chloride of cadmium was then 
added. 

' ' These three bottles vvere well agitated, securely sealed, 
and transported to the laboratory. From each, the precip- 
itate was filtered, washed, dissolved, and oxidized by 
fuming nitric acid and potassium chlorate, filtered, and 
the sulphuric acid determined in the filtrate with barium 
chloride. 

" No. 1. This precipitate contained the sulphur, existing 
in the form of sulphides and hyposulphites. 

"No. 2. Contained the sulphur existing in the form of 
sulphides, including the free sulphuretted hydrogen. 

"No. 3. Contained the sulphur present in the form of 
sulphuretted sulphides. The difference between No. 3 
and No. 2 indicated the amount of sulphur as free sul- 



196 MINERAL WATER. 

phuretted hydrogen ; and by deducting No. 2 from No. 1, 
the amount of hyposulphites was ascertained. 

u In the original nitrate from No. 1, the sulphuric acid 
was determined, after removing the excess of silver by 
hydrochloric acid." 

The changes made in Simmler s method were suggested 
by Wm. H. Chandler. Bromine may be used instead of 
nitric acid and potassium chlorate in oxidizing the pre- 
cipitates containing sulphur. 



CHAPTER XXXII. 

SUPERPHOSPHATE OF LIME. 

{For Agricultural Purposes.) 

It is so called from the fact that by treatment with acid 
the common tri-calcinm phosphate (bone phosphate) is. 
converted, according to the quantity of acid used, into 
either mono-calcium, or di-calcium, phosphate. If a suf- 
ficient quantity of sulphuric acid, for instance, be used, all 
the calcium will be withdrawn, and only phosphoric acid 
be left. The treatment for the production of soluble phos- 
phate or superphosphate is represented by the following 
equation : 

Ca 3 (P0 4 ) 2 +2H 2 S0 4 =2CaS0 4 +CaH 4 (P0 4 ) 3 . 

This is theoretical, and is rarely carried out in the manu- 
facture of fertilizers. There is usually some bone phos- 
phate unconverted, owing to the use of an insufficient 
quantity of acid. Suppose some tri-calcium phosphate to 
remain mixed with mono-calcium phosphate, and reaction 
to take place between them, as represented by the follow- 
ing equation : 

Ca 3 (P0 4 ) 2 +CaH 4 (P0 4 ) 2 =4CaHP0 4 . 

The result is a phosphate called by the names "re- 
turned," "reduced," "reverted," "precipitated." Tri- 
calcium or bone phosphate is insoluble in water, and di- 
calcium, or precipitated, very slowly soluble. Con- 
sequently, the value of the fertilizer depends chiefly upon 
the quantity of soluble phosphate present. The sample 
should be thoroughly mixed to insure that the portion 
taken for analysis fairly represents the average quality. 

Commercial superphosphate of lime always contains 
more or less moisture, which may vary greatly on keeping 
the sample. To avoid error from this source, a portion 



198 SUPERPHOSPHATE OF LIME. 

s 

should be taken for the determination of moisture (by- 
drying 1 gm. at 100° C, until it ceases to lose weight), at 
the same time that portions are weighed out for the deter- 
mination of the other constituents. Some chemists prefer 
to determine the moisture on a larger portion of the 
sample as received (up to 10 gms. or more) and then to dry 
half a pound or more of the sample on the water-bath, 
pulverizing and mixing it as it dries, and to use portions 
of the sample thus dried for determination of the moisture 
left, and for phosphoric acid, etc. (Stillwell, Proc, Am. 
Chem. Soc, II., 64.) The results must be calculated back 
so as to show the composition of the moist sample (as 
received). 

There are two methods of determining the different phos- 
phates present in a fertilizer usually followed by chemists, 
as follows : 

First Method. — Weigh 1 gm. of the superphosphate, 
transfer it to a shallow mortar, rub up with 50 c. c. of warm 
water (of a temperature of about 60° C), and pour the 
turbid fluid on a filter ; then add 50 c. c. more warm water, 
triturate again, and pour the water containing the finer 
particles of the material on the filter. Repeat this treat- 
ment with 50 c. c. more warm water, pour all the contents 
of the mortar on the filter, and wash with enough warm 
water to make the volume of fluid equal to 200 c. c. There 
will now be a filtrate containing the soluble phosphoric 
acid, and a residue containing the insoluble and precipi- 
tated phosphoric acid. 

Soluble Phosphoric Acid. — To the filtrate containing 
the soluble phosphoric acid add 4 or 5 gms. of sodium 
nitrate, and the same quantity of sodium carbonate, evapo- 
rate to dryness, fuse to destroy the organic matter extracted 
by the water, the heat of an open Bunsen burner being 
sufficient, remove the fused mass from the crucible with 
hot water, boil, and filter, if necessary. As nearly all of 
the phosphoric acid in superphosphates is soluble, and is 
consequently in this solution, dilute to 1 litre, and take 



PRECIPITATED AND INSOLUBLE PHOSPHATE. 199 

200 c. c, or one fifth of it, for phosphoric acid, to be 
determined by means of ammonium molybdate. 

The largest amount of phosphoric acid that can be 
present in pure bone phosphate is less than 46 per cent. 
As all, however, is rarely converted into soluble phosphate, 
and as there is usually a large amount of other substances 
present, it may be safely assumed that 50 c. c. of ammo- 
nium molybdate solution, 1 c. c. of which will precipitate 
1.3 milligrammes of phosphoric acid, is sufficient in all cases 
to precipitate the soluble phosphoric acid in one fifth of 
a gm. of superphosphate. 

Precipitated Phosphoric Acid. — Wash the residue con- 
taining the insoluble and precipitated phosphoric acid 
into a beaker, add a solution of 15 gms. of ammonium 
citrate in 50 c. c. of water (equivalent to sp. gr. 1.09), warm 
at a temperature of 60° C. for three quarters of an hoar, fil- 
ter and wash with about 150 c. c. of water of 60° C. Treat 
the filtrate as before with nitrate and carbonate of sodium 
(4 or 5 gms. of each), evaporate to dryness, fuse, take up 
with water, acidulate with nitric acid, boil, filter if neces- 
sary, and, as the amount of precipitated phosphoric acid is 
small, treat the whole solution with about 25 c. c. of am- 
monium molybdate solution, determining the phosphoric 
acid as usual. 

Insoluble Phosphoric Acid. — Fuse the residue left after 
extracting the soluble and precipitated phosphoric acid, 
with sodium nitrate and carbonate (4 or 5 gms. of each), 
over a common Bunsen burner, remove the mass from the 
crucible with water and nitric acid, boil, and filter if neces- 
sary. As the amount of insoluble phosphate is small, use 
all the solution for determining the phosphoric acid. Add 
to the solution about 25 c. c. of ammonium molybdate solu- 
tion, and proceed as usual. 

Second Method. — A better method is the one adopted 
by a committee of German chemists and reported by Frese- 
nius, one of the number, in the Zeit. fur Anal. Chem., 
Vol. VII, p. 304. See also Am. Chem., October, 1871. 



200 SUPERPHOSPHATE OF LIME. 

Treat 1 gm. with water alone, as directed in first method, 
to dissolve out the soluble phosphate, and, after drying, 
fuse the residue with nitrate and carbonate of sodium 
(about 4 or 5 gms. of each), dissolve the fused mass 
with water and nitric acid, and treat the whole solu- 
tion for phosphoric acid, as in the first method, 
with ammonium molybdate. This will give the insol- 
uble and precipitated phosphoric acid. At the same 
time, treat another gm. with water and ammonium 
citrate, as in the first method, to remove the solu- 
ble and precipitated phosphoric acid, and fuse the dried 
residue as before. As the insoluble phosphoric acid is 
small in amount, determine it in the whole solution as 
before. 

At the same time that the two portions are being treated 
for insoluble phosphoric acid, and for insoluble and pre- 
cipitated phosphoric acid (together), fuse another gm. of 
the superphosphate with nitrate and carbonate of sodium 
(5 gms. of each), bring into solution with water and nitric 
acid as before, dilute to 1 litre, and in 200 c. c. , equivalent 
to one fifth of a gm. , determine the total phosphoric acid. 

By deducting, from the amount of total, the amount of 
insoluble and precipitated, that of soluble phosphoric acid 
is estimated. 

By deducting, from the amount of insoluble and precipi- 
tated, that of insoluble, the amount of precipitated phos- 
phoric acid is estimated. 

In £ases where iron and aluminum are not present, phos- 
phoric acid may be determined volumetrically, by means 
of uranium, with sufficient accuracy for determining the 
value of superphosphate for fertilizing purposes. 

Solutions Required — A solution of uranium acetate. 
prepared by dissolving about 34 gms. in 1 litre of water. 

A solution of 10.085 gms. of pure crystallized liydro- 
disodium phosphate in 1 litre of water. The salt should 
be unefnoresced, coarsely powdered, and dried by pressing 
between folds of bibulous paper before weighing. 



VOLUMETRIC. 201 

A solution of sodium acetate, prepared by dissolving 
100 gms. of sodium acetate in water, adding 100 c. c. of 
acetic acid, and diluting to 1 litre. 

A solution of potassium ferrocyanide. 

Uranium Solution. — This is standardized by means of 
the sodium phosphate solution, of which 50 c. c. are in- 
troduced into a beaker, and heated to about 100° C. on a 
water-bath. 

After adding 5 c. c. of the sodium acetate solution, the 
uranium solution is run in from a burette, rapidly up to 
the amount of 15 c. c, and then, drop by drop (testing fre- 
quently by placing a drop of the sodium phosphate solu- 
tion on a white porcelain plate and adding a drop of the 
potassium ferrocyanide solution). As soon as the uranium 
is in excess, a reddish-brown coloration appears. The so- 
lution is then heated on a water-bath for a few minutes, 
and the test repeated. If the same reaction takes place, 
the titration is completed. The uranium solution should be 
of such a strength that 20 c. c. of it are equal to the 50 c. c. 
of rjhosphate solution. If this should not be the case, as 
the uranium solution is purposely made too strong, dilute 
accordingly, and repeat the titration on another portion of 
the phosphate solution, to insure correctness. 

Analysis. — This is made under conditions as nearly sim- 
ilar as possible to those under which the standardizing was 
performed. Add to the fluid to be examined, 5 c. c. of 
the sodium acetate solution, and proceed with the titration 
in the manner directed for standardizing the uranium solu- 
tion. 

As 1 c. c. of the uranium solution is equivalent to 0.005 
gm. of phosphoric acid, the calculation of the amount in 
the solution under examination is very simple. 

Chlorine. — Digest 1 gm. with about 50 c. c. of water, 
filter, wash, make the filtrate alkaline with sodium carbon- 
ate, add a little sodium nitrate, evaporate to dryness, fuse 
gently, take up with water, and determine the chlorine 
volumetrically with standard silver nitrate solution. 



202 SUPEEPHOSPHATE OF LIME. 

Sulphuric Acid. — Make a solution of 1 gm. as for 
chlorine, acidulate with, hydrochloric acid, and determine 
the sulphuric acid with barium chloride, as usual. 

Free Sulphuric Acid. — Make an aqueous solution of 
the superphosphate (1 or 2 gms.), evaporate slowly, until 
only a small quantity is left ; add about 7 volumes of 
absolute alcohol, and allow to settle in the cold for some 
hours. This precipitates all sulphates, and leaves in solu- 
tion, besides phosphates, the free sulphuric acid. Filter, 
wash with alcohol, add a large amount of water to the so- 
lution, carefully evaporate off the spirit, and estimate the 
acid in the solution in the usual manner by precipitation 
with barium chloride. (Crookes's Select Methods, p. 312.) 

Moisture. — Dry 1 gm. to constant weight at a tempera- 
ture of 100° C. 

Ammonia. — See analysis of guano. 

Alkalies. — Make a water solution of 2 or 3 gms. of the 
superphosphate, and determine the alkalies as in the 
analysis of water. 

Ash. — Incinerate 4 or 5 gms. of the superphosphate 
until all carbonaceous matter is consumed, cool, and 
weigh. If the ash is not of a light color, and free from, 
all black specks, repeat the ignition and weighing. 

For a method of making an exhaustive analysis of 
superphosphate, consult Fres., Quant. Anal., §235. 



REPORTING RESULTS. 

REPORT. 

Soluble phosphoric acid 

Precipitated phosphoric acid 

Total available phosphoric acid (P 8 6 )* 

Equivalent to bone phosphate [Ca 3 (P0 4 ) 2 ]* 



Insoluble phosphoric acid 

Equivalent to bone phosphate • 

Total phosphoric acid , 

Equivalent to bone phosphate 

Nitrogen , 

Equivalentto ammonia (NH 3 ) 

Potash (K 2 0) 

Equivalent to potassium sulphate (K 8 S0 4 ). 

Soda(Na 2 0) 

Equivalent to sodium sulphate (Na 2 S0 4 ). . , 
Water , 



*1 gm. P 2 5 is equivalent to 2.1831 gms. Ca 3 (P0 4 ) a , as will be found by 
stoichiometrical calculation. The factor is a convenient one to use in calculating 
results in this analysis or in that of guano. 



CHAPTER XXXin. 

MILK. 

The constituents are water, sugar, casein, and ash 01 
mineral salts. 

Weigh a small platinum dish ; then add a 5-gm. weight 
to those on the pan, and run in from a pipette enough 
milk to weigh a few milligrammes over 5 gms., determine 
the exact weight as quickly as possible and proceed. 

Water. — Evaporate over a water-bath, until the milk 
solids look dry ; then dry in an air-bath at 100° to 105° C. 
for one to one and a half hours, weigh, and dry again, for 
one half to three quarters of an hour, and weigh again. 
Repeat this treatment until the loss is less than 5 milli- 
grammes. 

Long heating should be avoided, as far as possible, as 
the sugar is apt to decompose and affect the results. 

Fat. — Weigh a small beaker and have ready a water- 
bath full of boiling water. Pour about 10 c. c. of ether on 
the milk solids, allow it to soak into the solids for a few 
minutes, place the dish on the water-bath, and keep it 
there until the ether boils. Then, after drying the bottom 
of the dish with bibulous paper, pour the ether into the 
weighed beaker, by means of a glass rod. If the milk 
solids flake off from the dish and become stirred up in the 
ether, a little care will suffice to prevent their being 
carried over into the beaker, as they sink rapidly in the 
ether. Repeat this treatment with ether about 6 times. 
Cover the beaker with a piece of filter-paper, and evaporate 
off the ether over hot water, being careful to have no flame 
near the beaker. When the ether is all gone, dry the 
beaker in an air-bath at 100° to 105° C, for about 15 
minutes. The residue is butter-fat. Should it contain 
any water, this should be driven off at as low a tempera* 



BUTTER — STTG AE — SALTS . 205 

ture as possible, that is, on a water-bath rather than in an 
air-bath. The milk solids, after treatment with ether, re- 
quire about 30 minutes' drying at 1 00° to 105° C. after the 
ether is all gone. When water is present, the direct 
determination gives results a little low, as the expulsion of 
the water appears to cause some decomposition of the 
butter, making the color dark, and giving it a peculiar 
odor. The determination by direct weight of the butter 
and that by loss seldom agree exactly, but usually within 
5 milligrammes or less. 

Sugar. — After extracting the butter and expelling the 
ether, nearly fill the dish with water, place it on a boiling- 
water bath, leave it there for about 20 minutes, pour off 
the water into a previously weighed dish of similar size, 
and place this also on a water-bath to evaporate. Repeat 
this treatment with water 4 or 5 times. After the contents 
of the dishes appear dry, leave them in an air-bath, heated 
to 100° C, for about 2 hours, cool, and weigh them. If the 
loss and direct weight agree, further drying is unnecessary ; 
otherwise, dry and weigh again. This gives the sugar and 
some soluble mineral salts. 

Ash of Sugar. — Ignite the dish containing the sugar at 
as low a temperature as possible, to avoid the loss of salts 
volatile at high temperature, such as potassium chloride, 
etc. The residue is the ash of sugar, and the loss by ig- 
nition, sugar. 

Casein. —After extracting the sugar, the residue left in 
the dish is casein, and some insoluble mineral salts. 

Ash of Casein. — Ignite the dish containing the casein, 
cool, and weigh. The residue will be ash of casein, and 
the loss by ignition casein. 

Ash or Mineral Salts. — Combine the weights of ash ol 
sugar and ash of casein. The sum will be the ash or 
mineral salts. 

For most purposes, the determination of water and 
butter is sufficient, giving water, butter, and solids, not 
fat. 



206 MILK. 

The British Society of Public Analysts fixes on maximum 
water as 88.5 per cent, and minimum butter as 2,5 per 
cent, and solids, not fat, as 9 per cent. (Qhem, News*, 
XXXI., p. 58, 1875.) 



CHAPTER XXXIV. 

ACIDIMETRY AND ALKALIMETRY. 

The solutions usually employed are of sulphuric acid, 
hydrochloric acid, oxalic acid, sodium or potassium hy- 
drate, and also of some substance which is colored differ- 
ently by acids and alkalies, such as litmus, cochineal, 
coralline, logwood, etc. 

A solution is styled normal when the molecular weight 
of the substance is the same as the number of milli- 
grammes of it in 1 c. c. of the solution. 

Half-Normal Sulphuric Acid. — This solution is pre- 
pared so as to contain 0.049 gm. H 2 S0 4 , or 0.040 gm. S0 3 , 
in each c. c. To 600 c. c. of water add about 20 c. c. of 
chemically pure concentrated sulphuric acid, mix well, 
and allow to cool. Measure out from the burette two por- 
tions of exactly 20 c. c, add to each portion 50 c. c. of hot 
water, and 40 c. c. of a saturated solution of barium 
chloride. Treat the precipitates of barium sulphate, and 
determine the sulphuric acid. If the precipitates do 
not differ in weight more than 0.010 gm., take the average, 
calculate the sulphuric acid in 1 c. c. of the solution and 
dilute, as directed afterward. 

Another method is as follows : 

Introduce about 3 gms. of dry C. P. sodium carbonate 
into a weighed platinum dish, heat to 180° C , or just be- 
low redness, for a few minutes, cool, and weigh, repeating 
to constant weight. This gives the weight of the sodium 
carbonate. Then add to the contents of the dish about 
30 c. c. of water, warm until the sodium carbonate is dis- 
solved, run in from a burette 20 c. c. of the sulphuric acid 
solution, keeping the dish covered while doing so, heat on 
a water-bath, with the cover on, until all free carbonic acid 
is expelled ; then remove the cover, after washing it and 



208 ACIDIMETRY AND ALKALIMETRY. 

allowing the washings to run into the dish, continue the 
evaporation to perfect dryness, heat, as in the first 
instance, to constant weight, either in an air-bath at 180° 
C, which is the better plan, or over an open flame, at a 
heat just below redness. The increase in weight is propor- 
tional to the amount of sulphuric acid used, so long as 
there is an excess of sodium carbonate over acid. 

The calculation of the value of the solution is made by 
the following proportion : The difference between the 
molecular weights of sulphuric acid and carbonic acid 
(36) is to the molecular weight of sulphuric acid (98) as 
the difference in the weights of dish and contents, before 
and after adding sulphuric acid, is to the weight of sul- 
phuric acid used, and as 20 c. c. of sulphuric acid were 
used, this result divided by 20 will give the value of 1 c. c. 
of the acid. 

It is customary to calculate the result in terms of S0 3 
instead of H 2 S0 4 . Suppose it is found by the experiment, 
that 1 c. c. of the solution contains 0.044 gm. of S0 3 instead 
of 0.040 gm., and, consequently, 100c. c. contain 4.400 gms. 
instead of 4 gms., then as 4 gms. are to 100 c. c. so are 4.4 
gms. 110 c. c. Therefore, 10 c. c. of water must be added 
to each 100 c. c. of the acid solution. To do this, fill a dry 
500 c. c. flask to the holding mark with the acid solution, 
pour it into a clean dry bottle, introduce into the flask 50 
c. c. of water, and pour this also into the bottle, after 
shaking well, pour the fluid back into the flask, and 
finally into the bottle for use. This is done to mix the 
fluid thoroughly. The bottle should be kept corked. 
This is what is called half -normal sulphuric acid solution, 
1 c. c. of which contains 49 milligrammes of H s S0 4 , or 40 
milligrammes of S0 3 . 

A solution of sodium carbonate may be used to obtain 
the solution of half normal sulphuric acid, thus : Heat a 
moderate amount of pure dry sodium carbonate in a plat- 
inum dish, until it begins to sinter together. Transfer, 
while hot, to a dry specimen tube or flask ; cork it up and 



STANDARDIZING. 209 

allow the salt to cool out of contact with the air. With 
this material make a half normal solution (53 grammes 
in 1 litre, or 26.5 grammes in 500 c. c, etc.). Mix the 
solution well and place some in a burette. Do the 
-same for the sulphuric acid solution made as first de- 
scribed. Run 10 c. c. of the sodium carbonate solu- 
tion into a beaker, add to it 10 c. c. of the sulphuric 
acid, or enough to render it acid, and boil to expel 
the carbon dioxide, which would otherwise affect the 
indicator and thus interfere. Then add a few drops 
of the indicator (cochineal is preferable in this case) 
and run in the sodium carbonate solution until the 
color shows that the solution is neutral. From the 
data thus obtained, calculate the amount of dilution re- 
quired for the sulphuric acid ; e. g., suppose 10 c. c. so- 
dium carbonate solution were used at first — then 10 c. c. 
sulphuric acid, and finally, after boiling, 2.3 c. c. sodium 
carbonate to effect neutrality, as shown by the color 
imparted by the indicator. Then 10 c. c. of the sulphuric 
acid neutralizes (10 -f- 2.3) 12.3 c. c. sodium carbonate 
solution. But the sulphuric acid should be half normal, 
or neutralize the sodium carbonate c. c. for c. c. There- 
fore 12.3 c. c. sulphuric acid ought to have been used if 
the solution was of the right strength ; or, every 100 c. c. 
of the acid solution should be diluted to 123 c. c. 

Measure the amount of the diluted acid on hand, dilute 
in the proportion indicated, rinse out the burette, mix well, 
and repeat the test in the same way, diluting again if 
necessary, until the solutions correspond exactly. The 
accuracy of the sulphuric acid solution should finally be 
verified gravimetrically by precipitation with barium 
chloride solution, etc. 

Normal Potassium Hydrate. — This solution is pre- 
pared so as to contain 0.05t)l gin. of potassium hydrate, 
(KHO) or 0.0471 gm. of potassium oxide (K 2 0.) 

Dissolve about 20 gms. of potassium hydrate in 300 c. c. 
of water, and when dissolved fill a Mohr burette with the 



210 ACIDIMETRY AND ALKALIMETRY. 

solution to the zero mark, and run it, drop by drop, inta 
a beaker containing 10 c. c. of the standardized sulphuric 
acid diluted to 200 c. c, and also a little cochineal solu- 
tion. Continue to add the alkaline solution until the 
yellow color, which is the color produced upon cochineal 
by acid, becomes carmine, showing that the fluid has 
become alkaline. Kepeat upon different quantities of 
acid. The color imparted to any number of c. c. of the 
sulphuric acid solution, by the cochineal, should change 
upon the addition of exactly the same quantity of alka- 
line solution. If it does not, the potassium hydrate solu- 
tion must be diluted until the two solutions agree. Sup- 
pose it is found by experiment that 10 c. c. of the acid so- 
lution requires only 8 c. c. of the alkaline, then, to every 
8 c. c, 2 c. c. of water must be added, or to each 100 c. c. 
of solution 25 c. c. of water. Employ the same method of 
diluting and mixing as in the case of standard sulphuric 
acid. Now, if 1 c. c. of the solution of potassium hydrate 
exactly neutralizes 1 c. c. of the solution of sulphuric 
acid, the quantity of K 2 and S0 3 must be exactly in pro- 
portion to their molecular weighty and as each c. c. of the 
acid solution was found to contain 0.040 gm. of SO s> 
each c. c. of the alkaline solution must contain 0.0471 gms. 
of K 2 0, as 80 parts of S0 3 are neutralized by 94.2 parts of 
K 2 0, or 0.040 gm. of S0 3 by 0.0471 gm. of K 2 0. It is some- 
times convenient to use potash lye of unknown strength 
for the preparation of the standard alkaline solution, in 
which case the quantity of alkali in a given volume can be 
determined approximately by finding the specific gravity 
of the lye with a hydrometer, and calculating the per cent 
of alkali by reference to the table in the Appendix, which 
gives the per cent of K 2 in solutions of different specific 
gravities. 

Indicators. — The coloring matters used to show when 
the fluid is acid or alkaline are so called. Although a 
great many have been prepared, only a few are in common 
use : 



INDICATORS. 211 

Litmus : To prepare this, Sutton directs to boil the lit- 
mus, reduced to coarse powder, two or three times with 
alcohol of about 80 per cent, and throw the liquid so 
obtained away. Then digest the litmus repeatedly with 
cold water until all soluble color is extracted, let the mixed 
washings settle clear, decant, and add to them a few drops 
of concentrated sulphuric acid until quite red, then heat 
to boiling ; this will decompose the alkaline carbonates 
and convert them into sulphates. Now cautiously add 
baryta water until the color is restored to blue or violet, 
let the barium sulphate settle perfectly, and decant into a 
proper vessel for use. The solution must be kept in an 
open bott]e, as it loses color in a closed vessel, although 
it will recover it upon exposure. Litmus cannot be used 
in the presence of carbonic acid ; consequently, the standard 
alkali, if litmus is used as the indicator, must be entirely 
free from it. 

Cochineal : Macerate, with frequent shaking, about 3 
gms. of good cochineal (in powder) with 250 c. c. of a mix- 
ture of 3 or 4 volumes of distilled water, and 1 volume of 
alcohol, and filter through Swedish paper. It keeps well 
inclosed bottles. It cannot be used in the presence of 
salts of iron, but is not affected by carbonic acid — at least, 
in moderate quantity. 

Logwood : Boil down a few shavings from the interior 
of a piece of logwood with distilled water, and mix the 
concentrated decoction with 1 to 2 volumes of alcohol. It 
must be kept unexposed to light. It cannot be used in 
presence of oxides of the heavy metals. 

Coralline: An alcoholic solution of this is extremely 
sensitive, and rapid as an indicator, and is particularly 
well adapted to the titration of vinegar and organic acids 
generally. 

Normal Hydrochloric Acid. — Mix 500 c. c. of water 
with 100 c. c. of pure hydrochloric acid of 1.12 sp. gr., run 
out from a burette 2 portions of exactly 20 c. c. each, and 
determine the amount of hydrochloric acid in each, with 



212 ACIDIMETRY AND ALKALIMETRY. 

silver nitrate, as directed in the analysis of barium chloride. 
If the two results agree closely, take the mean, calculate 
the amount of water necessary to make the solution of 
such a strength that 1 c. c. will contain 0.03646 gm. of 
hydrochloric acid. If a normal solution of potassium 
hydrate is at hand, also test a portion of the solution with 
it. The solutions should agree. 

Half-Normal Oxalic Acid. — Dissolve 63 gms. of pure 
crystallized oxalic acid in 1 litre of water and standardize 
the solution by titrating a portion of it with standardized 
potassium hydrate solution, or standardized potassium 
permanganate solution. 

These standard solutions may be kept in well-closed bot- 
tles for some time without appreciable change. Glass- 
stoppered bottles should be used for the acid solutions. 
The bottles containing the alkaline solutions should be 
closed with tightly-fitting corks which have been dip- 
ped in melted paraffine. 

These standard alkalimetric and acidimetric solutions 
find application in many of the processes of quantitative 
analysis, which it would be here unnecessary to specify. 
As samples of their application we will take the titration 
of crude sodium carbonate and the determination of the 
acidity of vinegar. 

Crude Sodium Carbonate. — Weigh out 5.3 gms. of the 
sample (= one twentieth of an equivalent of JSra 2 C0 3 ), dis- 
solve in a little hot water, filter, and wash the residue, 
bringing the bulk of filtrate and washings up to 100 c. c. 
Thoroughly mix this solution by pouring it backward and 
forward a few times from the flask to the beaker. Then 
take 10 c. c. of the solution, run in 10 c. c. of the half- 
normal sulphuric acid solution, dilute with about 40 c. c. 
of water, boil to expel excess of carbonic acid, add a few 
drops of cochineal, and then run into it normal potassic 
hydrate solution until the solution is exactly neutral. 
Repeat the operation with 2 or 3 other portions of 10 c. c. 
each, and take the average. The number of c. c. of sul- 



VINEGAK. 213 

phuric acid solution which have been neutralized by the 
solution of the sample, multiplied by 10, give at once the 
percentage of Na^COa present in the sample, since one 
twentieth of an equivalent of that compound was taken, 
and half -normal acid was used. We might have taken a 
round 5 gms., but in that case an unnecessary elabo- 
ration is introduced into the calculation. 

This method of weighing out one tenth or one twentieth 
of an equivalent in gms. of a substance, dissolving to 100 
c. c, and titering portions thereof, is usually the most 
convenient mode of procedure. In some cases, it may be 
convenient to make a one-twentieth normal solution of sul- 
phuric acid, or of potassium hydrate to correspond. 

For vinegar, weigh out in a stoppered flask 60 gms. of 
the vinegar, dilute to 1000 c. c. (or 30 gms., and dilute to 
500 c. a), mix thoroughly, and take 100 c. c. at a time for 
titration with the potassium hydrate solution. In this case, 
it is best to use coralline as an indicator, since the cochi- 
neal does not show a sufficiently marked deviation from the 
neutral tint, when only small amounts of free acetic acid 
are present. The number of c. c. of potassium hydrate 
solution required just to give a full alkaline* color, show 
the percentage of acetic acid present, since in this case an 
equivalent of acetic acid was weighed out, the percentage 
of acetic acid being usually small (about 3 to 10 per cent). 

In commerce, vinegars are often spoken of as " twenty 
grain," " thirty grain," " forty grain," etc. This means 
that one Troy ounce of the vinegar will exactly neutralize 
20, 30, 40, etc., grains of potassium bicarbonate (KHC0 3 ), 
and usually dealers desire to have the results expressed 
in this form. In such cases, it is easy to calculate, from 
the figures obtained, the number of grains of potassium 
hydrogen carbonate (bicarbonate) necessary to neutralize 
a Troy ounce by multiplying the percentage obtained by 
8.008. The reason for employing this factor is that there 
are 480 grains in a Troy ounce, and the number of grains 

* Neutral alkaline acetates have a slight alkaline reaction. 



214 ACLDIMETRY AND ALKALIMETRY. 

of KHCO3 necessary to neutralize 480 grains of pure acetic 
acid is found to be 800.8 by the following proportion : 
(HC 2 H 3 2 : KHCO3 =)60 : 100.1=480 : 800.8. 

The decimal place is changed two points in the factor 
because the figure expressing percentage is 100 times too 
great, being expressed as a whole number, instead of what 
it really is, parts in 100. Suppose, for instance, the per- 
centage found to be 6.5 ; then 6.5 X 8.008 = 52.052 grains 
of KHCO3 required to neutralize one Troy ounce. It is 
always best to verify the result by weighing out a Troy 
ounce (31.100 gms.), adding to it an amount of potassium 
hydrogen carbonate corresponding to the number of 
grains found (having determined the strength thereof by 
titration beforehand), boiling and testing the reaction of 
the solution, which should be just alkaline. If it is not, 
the test must be repeated. 

On account of the strong color of some vinegars, which 
prevents one from seeing the change of color in the in- 
dicator, some analysts prefer to distill the acetic acid off, 
and obtain a clear solution for titration (md. Blyth, 
Manual of Practical Chem., p. 210.) Of course, when it 
is desirable to know only the weight of acid in a given 
bulk of solution, as number of ounces in 1 gallon, the acid 
may be measured out, and diluted to any convenient 
strength, and aliquot portions taken for titration. 



CHAPTER XXXV. 

COMMERCIAL BICARBONATE OF SODA. 

WaHOO z . 

Moisture. — Weigh out 1 gm. in a platinum boat, and 
place the boat and contents in the centre of a piece of hard 
glass tubing about 8 or 10 inches long. Connect the tub- 
ing at one end, by means of a tightly-fitting tube and cork, 
with a bottle containing concentrated sulphuric acid to dry 
the air drawn through it, and at the other end with a cal- 
cium chloride tube, previously weighed and prepared by 
passing C0 2 through it as previously described. (Lime- 
stone, p. 59 ; Elementary Analysis of Sugar, p. 230.) The 
point of the calcium chloride tube should be passed 
through the cork, as a connection of rubber tubing is very 
likely to condense the water driven off, which is drawn 
into the tube then only with difficulty. The other end of 
the calcium chloride tube is then connected with an 
aspirator. Start the aspirator, and then apply the heat of 
a Bunsen lamp to the tubing where the boat lies. Raise 
the heat steadily until the tube about it is red hot. Keep 
it at that temperature for fifteen minutes or more. Then 
withdraw the heat and allow it to cool, still keeping the 
aspirator at work, until the tubing and calcium chloride 
tube are cool. Weigh the calcium chloride tube. The in- 
crease in weight is the moisture present in the sample. 
Withdraw the boat, and weigh it with its contents. The 
loss represents water plus half the carbon dioxide. This 
should be one half the amount of the carbon dioxide as 
determined afterward. 

Carbon Dioxide. — Introduce 0.5 gm. into the flask of a 
carbon dioxide apparatus, and 25 c. c. water containing 2 
c. c. concentrated sulphuric acid, or 5 c. c. concentrated 
nitric acid, and determine the C0 2 as usual in carbonates, 



216 COMMERCIAL BICAKBONATE OF SODA. 

by absorption in a tube of soda-lime, etc. (See Limestone, 
p. 59.) 

Hygroscopic Moisture. — Dry 1 or 2 gms. in the air-bath, 
at 100° C. to constant weight. The loss represents hygro- 
scopic moisture. This, deducted from total water deter- 
mined as above, gives water due to NaHC0 3 . Also, from 
the percentage of C0 2 calculate the water due to ]NaHC0 3 . 
These two results should agree — 

2NaHC0 3 =Na 2 0+H 2 0+2C0 2 . 

Soda Combined as Carbonate. — Dissolve 1 gm. in about 
100 c. c. of water, add cochineal solution, and then run in 
from a burette an excess of standard sulphuric acid solu- 
tion. (Alkalimetry, p. 207.) Boil out the carbon dioxide, 
and titre back with standard potash solution, and from 
these results calculate the amount of JSTa 2 combined as 
carbonate. 

Chloride. — Dissolve 1 gm. in 100 c. c. of water, just neu- 
tralize with HJST03, add a few drops of saturated solution 
of potassium chromate, (1 : 5) and titre with standard solu- 
tion of silver nitrate. The silver nitrate solution is made 
by dissolving 17 gms. pure crystallized AgN0 3 in one litre 
of water. It is standardized by testing it upon a solution 
of pure fused sodium chloride* containing 1 gm. in 
250 c. c. of water. The potassium chromate is used as an 
indicator, since the red silver chromate cannot form (per- 
manently) until all of the chloride has been precipitated. 
The silver solution is, therefore, added until the liquid has 
a reddish tinge, which cannot be removed by vigorous 
stirring. 

Sulphate. — Dissolve 3 or 4 gms. in water, acidulate 
slightly with hydrochloric acid, boil out the carbon di- 
oxide, and determine S0 3 as usual with BaCl 2 . 

Calculation : Calculate the CI to ISTaCl, the SO s to 

♦Most conveniently prepared by neutralizing pure sodium carbonate with 
hydrochloric i Ad, evaporating to dryness and fusing. All ordinary salt (table 
salt) contains small amounts of sulphates, chiefly calcium and magnesium, and 
other impurities, which cannot be separated without some trouble. — E. W. 



OALOULATION. 217 

.Na 3 S0 4 ' The Na 2 found by alkalimetrical titration repre- 
sents that combined as carbonate — mono or bi — since the 
neutral NaCl and Na 2 S0 4 have no effect. 

For calculating the amount of mono- and bicarbonate 

present let us take an example. Suppose we have found 

in a sample : 

Total C0 2 , 50.462 per cent; total Na 2 0, 37.894 per cent. 

First calculate the soda to C0 2 for monocarbonate 

(Na 2 0+C0 2 = Na 2 C0 3 )— A; 

then, (]S T a 2 : C0 2 =) 62 : 44 =37.894 : x, 
x x = 26.892 C0 2 . 
By subtracting this from the total C0 2 we obtain the 
excess of C0 2 due to bicarbonate, 50.462 — 26.892 = 23.570 
C0 2 . This represents just half of the C0 2 of the bicarbon- 
ate, since 2NaHC0 3 = (Na 2 0+C0 2 )+(H 2 0+C0 2 )— £. 

By doubling it, then, we get the whole amount of C0 3 
due to bicarbonate present in the sample. 
2X23.570 = 47.140 C0 2 . 
Calculate this to bicarbonate : 

(C0 2 : NaHCOg =) 44 : 84 = 47.140 : x 2 . 
x 2 = 89.995 per cent bicarbonate present. 
Calculate it also to Na 2 0. In the formula B, given above, 
2C0 2 balance one Na 3 ; therefore, 

(2C0 2 : Na 2 0=) 88 : 62 = 47.14 : x 3 . 
x 3 = 33.212 Na 2 in bicarbonate. 
The remainder of the Na 2 found (37.894—33.212 = 
4.682) is present as monocarbonate. 
Calculate accordingly : 

(NagO : Na 2 CO s =) 62 : 106 = 4.682 : x k 
x± = 8.004 per cent of monocarbonate present. 
To verify the calculation : 

C0 2 due to bicarbonate (x 2 ) 47.140 per cent 

C0 2 due to monocarbonate (a? 4 — 4.682) 3.322 " " 



Total CO a 50.462 «« 



u 



CHAPTER XXXVI. 

CHLOEIMETRY. 

Bleaching powder, commercially known as chloride of 
lime, consists of a mixture, according to some a combina- 
tion, of calcinm hypochlorite, CaCl 2 2 and calcium 
chloride, CaCl 2 . Its value depends upon the amount of 
chlorine set free when an acid is added, known as " avail- 
able chlorine," e. g. : 

Ca(C10) 2 ,CaCl 2 + 2H 2 S0 4 = 2CaS0 4 + 2H 2 + Cl 4 . 
Ca(C10) 2 ,CaCl 2 + 4HC1 = 2CaCl 2 + 2H 2 + Cl 4 . 

The available chlorine of bleaching powder is two 
atoms of CI for each atom of O in the hypochlorite, or, as 
the formula indicates, 2 and CU. 

The compounds known commercially as chloride of soda 
(Labarraque's solution) and chloride of potash (Javelle 
water) are similar in composition (NaG10,NaCl) and 
(KC10,KC1), and are the same as regards the ratio of O 
and CI. 

u Iodized Starch" Paper. — Rub up in a mortar 3 gms. 
starch with 50 c. c. warm water, wash the creamy mixture 
into a beaker containing about 200 c. c. boiling water, 
stirring well until solution is effected. Now add a solu- 
tion of 1 gm. KI and 1 gm. pure Na 2 C0 3 , and dilute to 
half a litre. Moisten strips of filter-paper with this solu- 
tion, and dry them for use, keeping them in a corked or 
stoppered bottle. 

Arsenious Acid Solution. — Weigh out 4.95 gms. pure 
pulverized white arsenic (As 2 3 ), transfer to a litre flask 
add about 25 gms. pure crystallized sodium carbonate, 
and 200 c. c. water. Boil gently, with frequent shaking 
until all is dissolved, cool, and dilute up to the litre 



ARSENIC METHOD. 219 

mark. One c. c. of this solution corresponds to 0.00355 
available CI, as may be seen from the following : 
As 2 3 + CaCl 2 2 ,CaCl 2 = As 2 5 + 2CaCl 2 . 
The four atoms of available chlorine in the bleaching 
powder correspond to the two atoms of O taken up by the 

As 2 3 . 

Molecular weight of As 2 3 = 198 
Molecular weight of Cl 4 = 142. 
Since 1 c. c. of the arsenious solution contains 

4.950 gms. taken 

0.00495 gm. As 2 3 = — ; then, 

6 1000 c. c. in 1 litre ' 

198 : 142 = 0.00495 : 0.00355. 

Analysis. — Weigh out 10 gms. of the bleaching powder, 
transfer to a mortar, add 50 or 60 c. c. of water, and rub to 
a cream. Allow the heavier particles to subside, decant 
the turbid supernatant fluid, add more water, rub up 
again, and continue thus until all the powder has been 
transferred to a litre flask. Fill the flask up to the mark, 
pour the contents into a beaker, mix it well, and take 
out 50 c. c. at a time for the analysis. The solution will 
always remain turbid, but this cannot be avoided, and does 
not interfere with the accuracy of the results, provided it 
is uniformly mixed. Into the 50 c. c. taken, run the 
arsenious solution, from a burette, until a drop of the 
solution taken out on a rod no longer produces a blue spot 
on the iodized starch paper, which has been previously 
moistened and spread out upon a white plate. 

The calculation is readily made. Fifty c. c. of bleaching 
powder solution, made in the way described, is equivalent 
to 0.5 gm. Suppose this takes 45 c. c. of the arsenious so- 
lution. Since 1 c. c. arsenious sol. = 0. 00355 gm. available 
CI, 45 c. c. = (45 X 0.00355) = 0.15975 gm. available CI. 

If then 0.5 gm. bleaching powder = 0.15976 gm. CI, 
lgm. == 0.3195 gm., 

or the bleaching powder contains 31.95 per cent of avail- 
able chlorine. 



220 CHLORIMETRY. 

CHLORIMETRY (IRON METHOD). 

Weigh out 10 gms. bleaching powder, place in a mortar, 
add 50 or 60 c. c. water, rub to a cream, allow the coarser 
particles to settle, pour off the turbid supernatant fluid 
into a litre flask, add more water, rub again, etc. , until all 
the powder has been transferred to the flask, fill up to the 
mark, pour the solution into a beaker, and mix well ; take 
out 50 c. c. for the analysis. 

Weigh out in the meantime 0.325 gm. piano-forte wire 
(= 0.324 gm. Fe) and dissolve it in 2 c. c. cone. H 2 S0 4 
diluted with 10 c. c. water in a small valved flask. Cool, 
fill the flask with cold water, and pour into a large beaker. 
ISTow add 50 c. c. of the turbid bleaching powder solution, 
pouring it in slowly, stirring all the time. Dilute to about 
500 c. c. Then, by means of a standardized solution of po- 
tassium permanganate (prepared as described under Am- 
monio Ferric Sulphate, p. 42), determine the amount oi 
iron still remaining in the ferrous form. 

The reaction is : 

4FeS0 4 +Ca(C10) 2 ,CaCl 2 +2H 2 S0 4 
= 2Fe 2 (S0 4 ) 3 +2CaCl 2 +2H 2 ; 
or four atoms Fe correspond to four atoms CI, 56 parts Fe 
equivalent to 35.5 parts CI. 

The mode of calculating results is best shown by example. 

Suppose 1 c. c. of the permanganate was equivalent to 
0.003 gm. Fe, and that it took 23.8 c. c. of that solution to 
oxidize the ferrous iron not acted upon by the bleach- 
ing powder used, in an amount equivalent to 0.5 gm. 
23.8 c. c. permanganate correspond to (23.8 X 0,003) or 
0.0714 gm. Fe remaining unoxidized. Then 0.324 (Fe 
taken) — 0.0714 (Fe unoxidized) = 0.2566 gm. Fe oxi- 
dized by bleaching powder. Since 56 parts Fe correspond 
to 35.5 parts CI, we have the proportion : 

56 : 35.5 = 0.2566 : 0.1601 gm. available CI. 

0.5 gm. bleaching powder contains 0.1601 available CI 

1 gm. contains 32.02, 

or 32.02 per cent available CI. 



CHAPTER XXXVII. 

ACETATE OF LIME. 

The best method of analysis consists in distilling a 
weighed quantity of the sample repeatedly with excess 
of hydrochloric acid, and in the distillate determining the 
acidity, and, since some of the hydrochloric acid distills 
over, that must also be determined and substracted from 
the amount of acid found. (Fres., Zeitschrift, V., 315.) 

The process is as follows : 

Weigh out 10 gms. of the sample, wash it into a small 
retort with 30 c. c. of water, connect the retort with a good 
Liebig condenser, add 8 c. c. hydrochloric acid, and distill 
to small bulk. Then add 30 c. c. of water, and distill 
again. Repeat this operation at least once more. Com- 
bine all the distillates and make the volume up to 500 c. c. 
By this time, you will have all the acetic acid from the 
sample as acid in the distillate. Take two portions of 100 
c. c. each from the distillate. In one portion (representing 
2 gms. of the sample), determine the acidity by titration 
with normal potassium hydrate solution. The result 
would show the amount of acetic acid obtainable from 2 
gms. of the sample, were it not that some of the hydro- 
chloric acid used has also distilled over. Therefore, in the 
other 100 c. c. we must determine the amount of hydro- 
chloric acid present. For this we use the tenth normal 
argentic nitrate solution (volumetric). The solution must, 
however, be first rendered neutral. For this purpose we 
use pure calcium carbonate in excess, which must be care- 
fully tested for chlorides, none of which, of course, should 
be present. About 5 gms. of calcium carbonate mil be 
amply sufficient. Stir it in well, warm up the solution, 
add a few drops of potassium chromate, and test with the 
tenth normal silver nitrate solution as described (p. 215). 



222 ACETATE OF LIME. 

Since we use a tenth normal solution, divide the number 
of c. c. used by 10, and then subtract the result from the 
number of c. c. of normal potassium hydrate solution 
used. The remainder gives the number of c. c. of potas- 
sium hydrate solution neutralized by the acetic acid from 
2 gms. of the sample. From this, the amount of acetic 
acid and percentage of pure acetate of lime present can be 
readily calculated. 
For example, suppose 
100 c. c. of distillate neutralized 19. 9 c. c. normal KHO, 
and 100 c. c. " " " 5 c. c. tenth n. Ag]ST0 3 . 

Then, 19.9 — 0.5 =* 19.4 c. c. normal KHO neutralized by 

the acetic acid from 2 gms. of the sample, 
19.9 X 0.06 (equivalent, of HC 2 H 3 2 = 60) = 1.194 gms. of 
acetic acid in 2 gms. of the sample, 
1.194 X 5 = 5.97 gms. acetic acid in 10 gms. of sample, 
or X 50 = 59.7 " " " in 100 " " " 

Then (2HC 2 H 3 2 : Ca(C 2 H 3 2 ) 2 -) 120 : 158 = 59.7 : x. 
x = 78. 605 per cent Ca(C 2 H 3 2 ) 2 in the sample. 
(For other methods, seeFres., Zeitschrift^'XlII^ 153, and 
Am. Chem., VI, 294.) 



CHAPTER XXXVIII. 

GUANO. 

Phosphoric Acid. — Fuse 1 gm. with 5 gms. sodium car- 
bonate, and 5 gms. nitrate in a platinum crucible over a 
Bunsen burner, removing the flame as soon as the fusion 
is complete, which should be in about half an hour. 
Eemove the contents of the crucible with hot water, 
acidulate with nitric acid, and boil. The crucible can be 
cleaned with dilute nitric acid without injury. Filter out 
any siliceous residue which may remain undissolved, dilute 
the solution up to 1 litre, and determine phosphoric 
acid in one fifth (200 c. c.) by means of ammonium molyb- 
date, as usual, using about 50 c. c of the molybdate solu- 
tion. 

Ammonia. — To determine the ammonia or nitrogen, 
select a tube of hard glass, 15 or 18 inches long, draw one 
end of it to a line point, and to the other end fit tightly a 
cork, through which is passed a tube bent at right angles, 
the other end of which passes through a cork closing 
tightly one arm of a bulbed U-tube. Into the combustion- 
tube first slip a loosely-fitting plug of asbestos previously 
ignited, and then some three or four inches of dry soda 
lime. Weigh out 1 gm. of the guano, pulverize coarsely 
some of the soda-lime in a mortar, mix this soda-lime with 
the guano, and introduce the mixture into the combustion- 
tube. Enough soda-lime must be taken to make the 
charge fill the tube to within three or four inches of the 
open end. Then fill up with soda-lime to within about 
an inch of the end, place another plug of ignited asbestos 
at the end, and close with the cork carrying the tube. 

Now run into the bulbed U-tube 10 c. c. of half -normal 
sulphuric acid from a burette, adjust the cork carrying 
the connection to the combustion-tube, and lay the com- 



224 guano. 

bus tion- tube in the trough of the combustion-furnace, sup- 
porting the bulb-tube by a clamp. Begin to heat at the 
forward end (nearest the cork), and get the soda-lime, 
which is unmixed with the charge, white hot before the 
heat is applied to the charge mixed with the guano. Then 
carry the heat slowly back until the entire contents of the 
tube are at a white heat. Avoid, however, heating the end 
which is drawn to a point, lest the pressure in the tube 
cause it to blow out. Keep up the heat until no more 
bubbles of gas are forced through the acid in the bulb- 
tube. Then connect the other limb of the bulb-tube with 
an aspirator, start the aspirator slowly, and then break 
off the fine point of the combustion-tube, at the same time 
removing the heat. Draw a slow current of air through 
the tube until it is well cooled down, and then disconnect 
the bulb-tube and pour the contents into a beaker, rinsing 
it out well. Add a few drops of cochineal solution, and 
by means of normal KHO solution determine how much 
of the sulphuric-acid solution used has been neutralized 
by the ammonia thus obtained from the guano. From the 
data thus obtained the percentage of ammonia or nitrogen 
may be readily calculated. Thus, suppose 8 c. c. of the 
sulphuric acid remained unneutralized, 2 c. c, then, have 
been neutralized by the ammonia ; 1 c. c. = 0.049 H 2 S0 4 = 
0.017 NH 3 or = 0.014 1ST, and the guano contains 2 X 100 X 
0.017 = 8.4 per cent 1^H 3 , or 2.8 nitrogen (md. Fres., 
§186, §187.) 

Sulphuric Acid. — Fuse 1 gm. with 5 gms. sodium car- 
bonate and 2 gms. nitrate, in a platium crucible over a 
Eunsen burner. Wash the fused contents as completely 
as possible from the crucible with hot water, rinse out the 
crucible with hydrochloric acid, add it to the solution, 
acidulate with hydrochloric acid, boil, filter if necessary, 
and determine sulphuric acid with barium chloride as 
usual. 

Water. — Dry 1 to 2 gms. to constant weight, at 120° C, 
in a weighed capsule. The loss is water. Then ignite the 



ORGANIC MATTER, ETC. 225 

capsule at strong red heat to constant weight. The loss is 
organic and volatile matter, including ammonia. Deduct 
the ammonia found elsewhere, the difference is non-ni- 
trogenous organic and volatile matter. Of course, this is 
only approximate. The residue after .igniting is mineral 
matter, including phosphoric acid. Subtract the phos- 
phoric acid found. The difference is CaO,MgO,Fe 2 3 
Al 3 3 S0 3 Si0 3 . Report as mineral matter. S0 3 may be 
driven out by the ignition, if there is no more than enough 
CaO and MgO to saturate the phosphoric acid. A quali- 
tative test on a hydrochloric acid solution of the ignited 
residue will show whether all the S0 3 has been expelled. 

report. . 

Phosphoric acid (P 2 5 )* 

Ammonia (NH 3 )f , 

Sulphuric acid (S0 3 ) 

Water (H 2 O) 

Mineral matter -, 

Non-nitrogenous organic and volatile matter 

* Equivalent to phosphate of lime 

f " "nitrogen.,,,.,, ,,, , 



CHAPTER XXXIX. 

RAW SUGAR. 

The points usually determined in the ordinary commer- 
cial analysis are the amount of crystallizable cane sugar, 
glucose, water, and ash. 

The usual method of determining the amount of crystal- 
lizable cane sugar is by the saccharimeter or polariscope, 
an instrument whose use depends upon the different action 
of solutions of sugar on polarized light, and so constructed 
that the per cent of cane sugar is read off directly upon 
the scale. 

A certain amount of sugar to be examined (for the 
ordinary Soliel saccharimeter, 26.048 gms.), is dissolved 
in 80 c. c. of cold water, 2 or 3 c. c. of basic acetate of 
lead added, the solution diluted to exactly 100 c. c, and 
filtered through a large, dry, corrugated filter. The basic 
acetate (subacetate or triplumbic acetate), is prepared by 
digesting, at a moderate heat, 7 parts of finely powdered 
litharge, 6 parts of neutral lead acetate, and 30 parts of 
water. If the basic acetate does not clear the solution, or 
the solution filters badly, add a few drops of solution of 
sodium sulphate, prepared by dissolving 1 part of the 
salt in 5 parts of water. If any salt of lead pass through 
the filter, making the filtrate turbid, dip a rod into acetic 
acid, and stir the liquid with it. This will dissolve the lead 
salt and clear the solution. 

If the filtered liquid is too much colored for the sac- 
charimeter, filter it through bone coal equivalent in bulk 
to 8 or 10 c. c. The coal should be previously ground 
moderately fine, and heated for a few minutes, to a point 
just below redness, to expel moisture. Care must be taken 
not to heat the bone-black enough to burn the carbon, and 
turn it white, as it will then lose the power of decoloriz- 



POLAKISCOPE TEST — INVERSION. 22? 

ing sugar solutions. As the coal has the power of absorb- 
ing sugar from the solution, thereby rendering it weaker, 
the filtrate should be poured back on the filter several 
times before using it in the saccharimeter. 

The tube intended to hold the sugar solution should 
be first washed out with the same, and filled slowly 
to avoid the presence of bubbles of air. The glass caps 
should not be pressed on the ends of the tube with the 
finger, but slid on gently and cautiously, so as to exclude 
all air. 

To adjust the saccharimeter, fill the tube with pure dis- 
tilled water, and turn the instrument, until the semi-disks 
are of the same color. It should then read zero. Now 
fill the tube with the solution to be tested, having pre- 
viously washed it with the same. The 2 semi-disks will 
no longer have the same color. Turn the instrument by 
means of the button, arranged for the purpose, until they 
have the same color, and read on the scale the per cent of 
cane sugar. 

It is well also to test the instrument with a solution of 
sugar, of known value. The color to be used depends 
upon the preference of the operator. The rose tint is best 
adapted to most eyes, and has the advantage, that, with 
the slightest change in the instrument, one semi-disk 
becomes instantly red, and the other green. 

The amount of cane sugar in a sample of raw sugar can 
be estimated by first determining the per cent of invert 
sugar in a portion by the copper solution, as directed later, 
and then, after converting a portion entirely into invert 
sugar, again determining the per cent. The difference in 
the results is equivalent to the glucose produced by the 
conversion, which is to be calculated to cane sugar. One 
hundred parts of invert sugar correspond to 95 parts of cane 
sugar. 

To invert the cane sugar, dissolve 1 gm. of the sugar in 
100 c. c. of water, add 1.2 c. c. of concentrated sulphuric 
acid, and heat on a water-bath for half an hour, replacing. 



228 RAW SUGAR 

from time to time, the water lost in evaporation. Neutral- 
ize the free acid with a dilute solution of sodium carbon- 
ate, dilute to 200 c. c, and proceed as directed. 

The determination of glucose requires a solution of cop- 
per sulphate, and an alkaline solution of Rochelle salt 
(sodium and potassium tartrate). These solutions, when 
mixed, constitute what is called Fehling's solution. It is 
better, however, to keep them separate (combining only 
when required), as the mixture is apt to decompose, if kept 
long. 

To prepare the copper solution, dissolve 34.640 gms. of 
copper sulphate in 2u0 or 300 c. c of distilled water, cool, 
dilute to exactly 500 c. c, and keep in a glass-stoppered 
bottle. Five c. c. of this solution will then correspond to 
0.05 gm. grape sugar. To prepare the Rochelle salt solu- 
tion, dissolve 68 gms. of pure sodium hydrate in about 400 
c. c. of distilled water, add 187 gms. of Rochelle salt, heat 
on a water-bath, with frequent stirring, until all is dis- 
solved, cool, dilute to exactly 500 c. c. and keep in a 
glass-stoppered bottle. 

To make the analysis, introduce 5 c. c. of the copper 
sulphate solution, 5 c. c. of the Rochelle-salt solution, and 
5 c. c. of water, into a 10-inch test-tube or tall narrow 
beaker, and also 2 or 3 small fragments of washed and 
ignited pumice-stone, to prevent bumping of the fluid when 
heated, boil and add (little at a time), from a burette, the 
sugar solution to be tested, which should not contain more 
than 0.5 per cent of sugar. If, upon trial, it is found that 
all the copper is precipitated by less than 10 c. c. of the 
sugar solution, dilute the solution with an equal quantity of 
water and repeat the test. If, on the contrary, it is found 
that more than 25 c. c. are required, make a solution of 
the sugar of twice the strength, and repeat. The liquid 
must be kept alkaline. Toward the end of the operation, 
a slight cloud is formed upon adding the sugar solution ; 
at the close, the fluid loses its blue color, becoming nearly, 
if not quite, colorless. If excess of sugar solution is 



GLUCOSE — MOISTURE — ASH. 229 

added, the fluid becomes yellow, and brown if very great 
excess is added. Violette says that the average of the 
readings when the cloud forms, and when the fluid becomes 
yellow, is the true one. 

To test the copper-sulphate solution, dry at 100° C. some 
pure powdered cane sugar, weigh 1 gm., dissolve it in 100 
c. c. of water, add 1.2 c. c. of pure sulphuric acid, heat on 
a water-bath for half an hour, cool, neutralize with sodium 
carbonate, dilute to exactly 200 c. c, and titre with it 5 c. c. 
of the copper- sulphate solution mixed with 5 c. c. of the 
Rochelle-sart solution and 5 c. c. of water. If the solution 
of copper sulphate is accurate, it should require 9.5 c. c. 
of the sugar solution. 

To determine moisture, dry a weighed quantity of the 
sugar to constant weight, at 100° C. It is well not to take 
more than 0.5 gm. of sugar, as the operation is sometimes 
very tedious, where a large quantity is used, and the dan- 
ger of decomposing the sugar by long-continued heating- 
great. The heat must not exceed 105° C, as a higher tem- 
perature will caramel the sugar. 

In determining the ash, different methods are used. The 
first consists simply in weighing out 3 or 4 gms. in a plat- 
inum dish, and burning at a low red heat until the ash 
appears white. This operation is extremely tedious, and 
involves some loss of alkaline salts in consequence of the 
prolonged exposure to a high temperature necessary. A 
method much used in France consists in adding a few c. c. 
of concentrated sulphuric acid to 3 or 4 gms. of the sugar 
in a platinum capsule, and incinerating as before. From 
the weight of the ash thus obtained one ninth is sub- 
tracted, and the figure remaining is reported as the ash of 
the sugar. The most accurate method consists in carboniz- 
ing the sugar at a high heat for a short time, pulverizing 
the carbon thus obtained, extracting from it the alkaline 
salts by boiling with water, filtering, evaporating, and 
gently igniting the filtrate in a platinum dish, and then 
incinerating the carbonaceous matter insoluble in water. 



230 RAW SUGAR. 

This gives the proportion of soluble and insoluble ash, 
their sum being, of course, equal to total ash. The three 
methods give results sometimes differing widely from one 
another when tried on the same sample. In any case, 
where carbonization of the sugar begins, the sugar is apt 
to boil up, and care must be exercised lest some loss may 
be experienced in consequence. 

To examine sugar or molasses for artificial glucose (made 
from starch) weigh out 18.86 gms. of the sample to be 
tested, dissolve in water, invert by acidulating and heat- 
ing, cool, neutralize with sodium carbonate, dilute to 100 
c. c, and examine in the polariscope at a temperature of 
92° C. The percentage of artificial glucose present will 
then be indicated on the scale. (See Journ. Am. Chern. 
Soc., Yol. I., p. 2.) 



CHAPTER XL. 

SUGAR (ULTIMATE ANALYSIS). 

Percentages of C, R, and 0.— The carbon and hydrogen 
are determined at one operation by combustion in a stream 
of dry oxygen, the resulting C0 2 and H 2 being caught 
in suitable apparatus and weighed in those combinations. 
The oxygen is determined by difference. Select a tube of 
hard glass about 28 inches long, and 5 or 6 tenths of an 
inch internal diameter, fit to each end corks through which 
are passed tubes of about 1 tenth inch internal diameter, 
and 3 or 4 inches in length. About 2 inches from the front 
end of the tube (the end to be attached to the apparatus 
for absorbing C0 2 and H 2 0), place a plug of asbestos, pre- 
viously ignited to remove all moisture and carbonaceous 
material. Back of this plug put enough freshly -ignited 
CuO to fill the tube a little more than half, and push down 
upon this another plug of ignited asbestos. Provide at 
the rear end of the tube two bottles, with corks and tubes, 
for drying the O and removing from it any traces of C0 2 it 
may contain, by bubbling it through the bottles, contain- 
ing, respectively, concentrated H 2 S0 4 and strong KHO, 
having the sulphuric acid next to the tube. For the froni" 
end, have a tube filled with neutral calcium chloride in 
fragments, through which a current of dry carbon dioxide 
has been passed for some time, followed by a current of 
dry air. To absorb the carbon dioxide, prepare a U-tube, 
filled with soda-lime, constructed in the same manner as 
given for the determination of C0 2 in limestone (p. 63) 
or carbon in iron (p. 106). The sugar, being previously 
dried thoroughly at 100° C, 0.250 gm. is then to be 
weighed out in a platinum boat. Weigh the calcium- 
chloride tube and the soda-lime tube. Connect the com- 
bustion-tube (laid in the trough of the combustion-fur- 



232 SUGAR (ultimate analysis.) 

nace) at the rear end with the bottles of sulphuric acid and 
potassium hydrate, and at the front end directly with the 
aspirator, heat it to redness, and then draw a current of 
air through it until cool. Then introduce the platinum 
boat into the rear end, replace the cork, and connect the 
calcium -chloride tube and soda-lime tube at the front end, 
connecting the last with the aspirator. Draw a slow 
current of air through the tube, and begin to heat the 
front end of the CuO, carrying the heat slowly back- 
ward toward the boat containing the sugar. At the 
same time, keep the . rear end over the tube mod- 
erately, carrying the heat slowly forward. Arrange it 
so that the CuO shall be heated highly before the sugar 
begins to burn. Just before the heat reaches the boat, 
attach the tube from the oxygen cylinder, and force a slow 
current of the gas through the tube. Heat the sugar very 
moderately, so that it will burn slowly and not force the 
gases off too rapidly. When it is completely consumed, 
which may be seen by the disappearance of the black car- 
bon, remove the heat, disconnect the oxygen cylinder, and 
draw a current of air through it until it is cool. Then 
detach the tubes and weigh. The increase in weight of 
the calcium-chloride tube represents water, from which 
the percentage of hydrogen may be calculated, the in- 
crease in weight of the soda-lime tube represents the car- 
bon dioxide, to be calculated to C. 



CHAPTER XLI. 

TURPENTINE (ULTIMATE ANALYSIS.) 

^10-" 16 

Percentages of C and H. — The process pursued is essen- 
tially the same as that in the ultimate analysis of sugar. 
A few modifications only are necessary, since in this case 
we are dealing with a volatile liquid instead of a solid. 
* The pieces of apparatus necessary, are the same as for the 
sugar analysis, with the exception of the platinum boat in 
which the sugar is weighed. Instead of this a small bulb 
of thin glass is prepared, the ' ' tail' ' of which is drawn to 
a long fine point. The extreme point is then broken off, so 
as to leave an opening into the interior, which should be 
as fine as a hair. The bulb is weighed and then warmed, 
and the end being immersed below the surface of some tur- 
pentine, the contraction of the air in the bulb, as it cools, 
will draw some of the liquid into the bulb. Before it is 
quite cold, withdraw the point from the turpentine, that 
the contraction may draw the liquid out of the "tail," 
leaving it clear. Then wipe the "tail" dry, and seal the 
end by a moment' s exposure to a blow-pipe flame. The 
glass should be so thin that this can be readily accom- 
plished. Weigh again. The increase in weight of the 
bulb gives the weight of the turpentine taken. Half -fill 
the combustion-tube with ignited copper oxide as before, 
drop in the bulb containing the turpentine, just crack it by 
a light blow from a glass rod, introduced for the purpose, 
and immediately pour down upon it some more copper 
oxide which has been ignited and cooled out of contact 
with the air. Conduct the remainder of the operation as 
in the case of sugar, carrying the heat back more slowly 
and carefully. A longer tube than that used for sugar 
analysis may be used with advantage. Carry the heat 
quite to the end of the copper oxide before stopping the 
operation. 



CHAPTER XLII. 

BONE-BLACK. 

Water. — Dry 1 gm. at 170° C. to constant weight. The 
loss is water. 

Carbon Dioxide. — Introduce into the flask of a C0 2 
apparatus 5 gms. of the finely pulverized black, add 30 
c. c. dilute hydrochloric acid, and determine the carbon 
dioxide by absorption in soda-lime. Calculate to CaC0 3 .* 

After the determination of the carbon dioxide in the 
manner first given (by absorption with soda-lime) pour the 
contents of the flask upon a filter and wash thoroughly. 
There will then be a residue and a solution. 

The residue consists of sand, clay, carbon, and insoluble 
organic matter. Wash it from the filter into a weighed 
platinum dish, allow it to settle, decant off the clear fluid 
as closely as possible without disturbing the residue, evapo- 
rate, dry at 170° C, and weigh. Weight == sand, clay, 
and carbon, plus dish. Ignite until all carbon is burned 
off, and weigh again. Weight = sand and clay, plus dish. 
Difference from above weight reported as carbon. In the 
solution add barium chloride, to precipitate the sulphuric 
acid, filter off, weigh the BaS0 4 , and calculate the sul- 
phuric acid to CaS0 4 . Dilute the filtrate to 500 c. c, and 
divide into two parts ; A = 100 c. c, B = 400 c. c. 

A. — Dilute to 500 c. c, and take 100 c. c. (representing one 

* In most, if not all, sugar-houses, the common method of determining car- 
bon dioxide is a volumetric process, the volume of gas evolved being measured 
by an instrument invented by Dr. C. A. Scheibler, a full description of which will 
be found in Fres., Quant. Anal., § 237, or in Crookes's Special Methods, p. 390. 
From the latter work, p. 397, the following table of corrections for temperature 
of the volume of gas obtained has been taken : 



TABLE FOR SCHEIBLER'S APPARATUS. 



235 



82 



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236 BONE-BLACK. 

fifth of a gm.), add about 10 c. c. cone, nitric acid, evapo- 
rate nearly to dryness to expel hydrochloric acid, add 50 
c. c. ammonium molybdate, and determine phosphoric acid 
as usual. Calculate to Ca 3 (P0 4 ) 2 . 

B. — Add 4 or 5 c. c. cone, sulphuric acid, evapo- 
rate nearly to dryness, add 25 or 30 c. c. water, and 100 
c. c. alcohol. The precipitate is BaS0 4 -f-CaS0 4 . Filter 
out, wash well with water, from the filtrate boil out the 
alcohol, reduce the iron with zinc and platinum, as in iron 
ore, and titre with potassium permanganate. Calculate 
to FeO. 

Nitrogen, chlorine, and alkalies may sometimes be re- 
quired. 

For chlorine, boil 5 gms. with nitric acid, filter, and 
determine by Ag!N"0 3 in the filtrate. For nitrogen and 
alkalies, see Guano and Superphosphate, pp. 197 and 222. 

A mechanical test of the size of the black is frequently 
made. For this purpose 100 gms. is weighed out and 
shaken in a series of ten wire sieves, the meshes of which 
are of gradually decreasing size, thus : 

No. 1 has 6 holes to linear inch. 



cc 


2 


u 


8 


a 


3 


a 


10 


a 


4 


u 


20 


a 


5 


a 


30 


u 


6 


a 


40 


a 


7 


u 


50 


a 


8 


a 


60 


\i 


9 


a 


80 


c< 


10 


a 


100 


•in 


e 


u 


120 



To get the average fineness of the black, multiply the 
weight left on each sieve by the number of meshes of that 
sieve to the inch, add the products together, and divide by 
100. 

To determine the weight of a cubic foot of the black, 
select a small porcelain capsule, weigh, then fill with the 



ABSORPTIVE AND DECOLORIZING POWER. 237 

black, level with, the brim without shaking down, weigh 
again, and then weigh the capsule full of water ; and this 
gives all the data necessary for calculating the specific 
gravity of the black when lying loosely. From this the 
weight of a cubic foot may be calculated. That of a cubi^ 
foot of water is usually taken as 62^ lbs. (62£ lb»- Watts 1 s 
Diet, V., 1010.) 

To determine the absorptive powe^ ot the black — rhe 
porosity — weigh out 20 gms. in a funnel, drench with 
water, allow the surplus water to drain off, and weigh 
again. The amount of water retained shows the degree 
of porosity. 

Decolorizing Power. — Make a solution of raw sugar 
of 10° Be. (about 1.07 sp. gr.), take 20 to 50 gms. of the 
sample, and the same amount of a bone-black the power 
of which is known. Wet the samples down well with the 
raw-sugar solution, and pass equal amounts of the solution 
through each sample. Compare the depth of color left in 
the sugar solutions, after filtration, with one another by 
means of a Duboscq colorimeter. 

Completeness of burning is determined by boiling a 
portion of the sample with solution of sodium or potassium 
hydrate. The deeper the coloration of the alkaline solu- 
tion the less complete the burning has been, since organic 
matters occurring in the coal, which have been incom- 
pletely carbonized, impart a strong color to solutions of 
caustic alkalies. 

Completeness of Washing. — Wash with hot water, and, 
after cooling, test the density of the wash-water. 



CHAPTER XLIII. 

COAL. 

Moisture. — Dry 2 gms. of the coal, finely pulverized, in 
a weighed platinum crucible at 115° C. 3 for half an hour, 
cool, and weigh. Dry again for 15 minutes at the same 
temperature, cool, and weigh again. Repeat this until the 
weight begins to increase, indicating incipient oxidation. 
From the lowest weight thus obtained calculate the per- 
centage of moisture. 

Volatile Combustible Matter. — Ignite the above crucible 
and contents for three minutes (keeping the crucible 
closely covered) in the strongest heat of a good Bunsen 
burner, then at once ignite for the same length of time 
over the blast-lamp, cool, and weigh. The crucible should 
be kept covered throughout this operation. The loss is 
volatile combustible with half the sulphur. For anthracite 
or coals containing no bituminous matter, this operation 
may be omitted as unnecessary. 

Fixed Carbon. — Remove the cover, and burn off the 
remaining carbon over a Bunsen burner until nothing 
remains but the ash. The loss is fixed carbon with the 
remainder of the sulphur. The final weight, less the weight 
of the crucible, gives the ash. 

Sulphur. — Pulverize the coal finely, weigh out 2 gms. 
and mix it thoroughly in a convex cover with 16 gms. 
sodium carbonate and 16 gms. sodium nitrate, also finely 
pulverized. Now, with a spatula introduce a little of the 
mixture into a large platinum crucible, cover it, and heat 
until deflagration commences, when the flame should be 
removed. As soon as the violence of the deflagration has 
ceased, add a little more of the mixture, and apply the 
flame again until deflagration again occurs. Repeat this 
until all of the mixture has been transferred to the cru- 
cible. Heat after the last violent deflagration has ceased,, 



KEEPING NOTES — SPECIFIC GRAVITY. 239 

until the mass is in complete fusion to insure oxidation of 
the sulphur. Dissolve out the contents of the crucible in 
boiling water, acidulate with HC1, boil to remove the lower 
oxides of nitrogen, if anything remains undissolved, filter 
and wash. In the solution, precipitate the sulphur (now 
present as sulphate) with BaCl 2 in the manner already 
given (p. 18.) 

The most convenient method of keeping the notes on a 
coal analysis are as follows, an example being given to 
show how the calculation is made : 

Weight of crucible and coal 32.0000 gms. 

"crucible 30.0000 

Goal taken 2.0000 

Weight of crucible + coal 32.0000 

. " . " " after drying 31.9920 

Loss = H a O 0.0080 0.40 per cent. 

Weight of crucible + coal dried 31.9920 

" ignited (closed) 31.4480 

Loss = volatile combustible + %&.:.. 0.5440 27.20 " 

Weight of crucible + coal ignited (closed). . . . 31.4480 
" ignited (open) 30.1000 

Loss = fixed carbon + % S 1.3480 67.40 " 

Weight of crucible + contents ignited (open). 30.1000 
- " " 30.0000 

Residue = ash 0.1000 5.00 

Sulphur 1 

REPORT. 

Moisture 0.40 per cent. 

Volatile combustible (27.20 less 0.5 or ^ S) 26.70 

Fixed carbon (67.40 less 0.5 or % S) 66.90 

Ash 5.00 

Sulphur 1.00 

100.00 

Weight of a Given Volume of the Coal (1 cubic yard). — 
By weighing a fragment of the coal suspended from the 
balance by a hair in air and then in water the specific 
gravity may be obtained. The weight of a cubic yard may 



240 COAL. 

/hen be calculated, e. g.: Suppose the specific gravity to be 
1.3488. 

Now, 1 cubic foot of water weighs 62. 355 lbs. ( Watts' s 
Diet., Y., p. 1010), and 1 cubic yard weighs 62.355 X 27 
= 1683.585 lbs. . • . 1 cubic yard coal weighs 1683.585 X 
1.3488 = 2270.819 lbs. or, leaving off the decimals 2271 
lbs. The weight of 1 cubic foot of water may be regarded 
as 62i lbs. 

Ultimate or Elementary Analysis of Coal. — This is 
conducted in the same manner as for sugar, which see 
p. 230. 

Heating Power. — Berthier's method, by the reduction 
of lead oxide (Handb. der Met. Analyt. Chem., I., 207; 
Kerl., Hutten-Tcunde, I., 218), is thus described: 

Mix 1 gm. of the finely pulverized coal carefully 
with not less than 20 or more than 40 times its weight of 
finely sifted litharge containing no metallic particles, 
place the mixture in a small crucible, and cover it with 30 
times its weight of litharge. That the mixture may not 
boil over, the crucible should be only about half full. Cover 
the crucible, and heat gradually in a muffle or wind fur- 
nace to red heat. If the heat is raised too rapidly, com- 
bustible gases escape, or the mass may boil over. In 
using a wind furnace, the crucible should be placed on a 
fire-brick, resting on the grate bars supporting the glow- 
ing coals. Shake coals around it until only the top of the 
crucible projects. When the mass, which at first swells 
up, is fused, cover the crucible entirely with coals, and 
increase the heat for ten minutes to collect the lead in a 
button, and then take it out. The whole operation lasts 
from forty-five minutes to one hour. Break up the cru- 
cible, clean the button from adhering lead oxide by means 
of a brush, and weigh. To obtain a reliable average make 
two to four tests. Forchammer (Bgwfd., XL, 30) recom- 
mends, instead of litharge, a mixture of 3 parts litharge 
with 1 part lead chloride, which fuses more readily and 
requires only ten minutes for the operation. As unity we 



HEATING POWER. 241 

refer to carbon, which reduces 34 times its weight of lead. 
Sugar carbon gives nearly this quantity of charcoal ; with 1 
to 1.5 per cent ash, only 29 to 30 parts. If we assume 1 
caloric as 8086 (Favre and Silbermann) every part of lead 

QfxOfi 

produced — -~r = 230 heat units. Since this is based 

upon Welters' s* law, it gives no absolutely correct results, 
but they do not differ appreciably from the truth, so that 
this process on account of its simplicity is still of value, 
and it is still frequently used. (Winkler Erdm. Jr. fvc 
PraM. Chem., XVII., 65; V. Hauer* Oesterr. Zeitschr. 
€LIIL, 34, 156, 249.) The results are at most one ninth toe 
low, as estimated against the calculation from elementary 
analysis, and according to Stolzel (Dingl. Polyt J 
€XLVL, 138) are the closer the higher the percentage of 
carbon, and the greater the care exercised to avoid loss of 
carbon monoxide. 

* Welters's law may be briefly stated thus : The absolute heating effects of car- 
bon and hydrogen stand in direct relation to the amounts of oxygen taken up in 
burning. Thus, one part by weight of H stoichiometrically calculated requires 
thrice as much O as one part of C, e. g. : 

2 parts hydrogen take 16 parts O to form H 2 or 1 pt. H takes 8 pts. O. 
12 " carbon " 32 " " " CO, " 1 pt. C " 2% " O. 
. \ Heating effect of H : Heating effect of C '= 3 : 1. 

Experimental researches show the absolute heating effect of H as compared 
with C to be 4.2 : 1 (Favre and Silbermann ib.). 



CHAPTER XLIV. 

PETROLEUM. 

Petroleum consists of a mixture of hydrocarbons, prin- 
cipally of the so-called paraffine series, C n H 2n+ 2, in which 
the temperatures of boiling or melting increase as the 
number of atoms of carbon in the molecule increase. 
Thus, the first four of the series are gaseous at ordinary 
temperatures, the next two or three boil at a temperature 
below that of boiling water, the rest at a still higher tem- 
perature. As the number of carbon atoms in the molecule 
increase, the boiling point becomes higher and higher. 
'?hose members of the series containing twenty atoms of 
carbon or more in the molecule are solid at ordinary tem- 
peratures (commercial paraffines), etc. (vid. Fowne's Ele- 
mentary CTiem.). 

The chief value of a petroleum lies in the amount and 
quality of burning, and heavy paraffine oil which can be 
obtained from it. This is determined by subjecting the 
oil to what is called ''fractional distillation," keeping the 
portions distilling off at different temperatures apart from 
each other, and then determining the amount and quality 
of the fractions. What distills off first is known as the 
naphtha, and is inferior in value. The last portions, after 
distilling off the heavy paraffine oils, have also little or 
no value. The process is thus conducted : 

The gravity of the oil at 60° F. is first taken. Then 500 
or 1000 c. c. of the oil, preferably the larger quantity, is 
weighed, and placed in a retort connected with a good 
Liebig condenser. A cork, carrying a thermometer which 
will register temperatures at least as high as 500° F., is 
then fitted to the tubulure of the retort and heat is applied. 
The oil is gradually raised to the temperature of boiling. 
Being a mixture of hydrocarbons having different boiling 
points, the temperature does not remain constant, but 



DISTILLATION. 243 

steadily increases. As soon as the thermometer indicates 
150° F., the receiver is changed, and another is substituted. 
This is again changed at 250° F. These first two fractions 
are the light and heavy naphtha. The fraction between 
250° and 400° is the light-, and that between 400° and 500° 
the heavy -burning oil. If it is only desired to determine 
the quantity and quality of the illuminating oils which 
the petroleum will yield, we may stop here. If it is de- 
sirable to go on, the heat is removed for a moment while 
the thermometer is taken out and replaced by a close-fit- 
ting ground-glass stopper. The heat is then replaced, and 
the distillation continued until but a small amount is left 
in the retort. In some cases, two or three fractions are 
made of the last portion coming off after 500°. Having the 
fractions, the next step is to determine their amount and 
quality. Measure and weigh each one, and take the 
specific gravity as a check on the results. It must be 
remembered that loss is involved in every transfer of the 
oil from one vessel to another ; therefore the best plan is to 
weigh the receivers for the fractions beforehand. The 
specific gravity is usually reported in degrees Baume. 
Since, however, there are several tables giving the com- 
parison of Baume degrees and specific gravities which 
differ from one another more or less widely, it is well also 
to record the specific gravity, which may be ascertained 
most readily and accurately by weighing a small piece of 
glass or brass suspended from a hair in the oil, then in air* 
and in water. 

REPORT. 

Gravity of the oil °Baume ( = sp. gr ) 

The oil was found to contain : 

Temperature. , Per Cent > , — Gravity — > 

Fahr. By Vol. By Wt. Be. =Sp.Gr. 

J?* ht ' I Naphtha 70°tol50° 

Heavy, y JNapntna 150° to 250° 

Light. ) n „ min „ ., 250° to 400° 

Heavy, f Burmn S ol1 400° to 500° 

Parafnne oils 500° upward 

Residue (cokings) 



244 PETROLEUM. 

Refined burning oils sometimes require to be tested for 
"flashing" and "burning" points ; or, in other words, it 
may become necessary to determine at what temperature 
the oil will evolve an inflammable vapor, and at what tem- 
perature it will take fire when brought near a flame. The 
test is made by placing a small portion of the oil in a glass 
vessel surrounded by water, immersing a thermometer in 
the oil, and slowly heating the water, which, in turn, im- 
parts heat to the oil. The oil should be frequently stirred 
to insure uniform heating, and from time to time a small 
flame is brought near the surface of the oil. The tempera- 
ture should not be raised faster than 3° in five minutes. 
When the "flashing point" is reached, on the approach 
of a flame, a light blue flame runs over the surface of the 
oil, accompanied with a slight explosive sound. The indi- 
cation of the thermometer is then noted. The heat is still 
raised until the application of the flame will set the oil on 
fire, and it will remain burning when the flame is removed. 
The indication of the thermometer is then noted as the 
"burning point." The operation should be conducted in 
So place not exposed to draughts. The flame should not 
be frequently applied to the surface of the oil, lest the 
upper layer of the oil should be heated up to the flashing 
point, while the lower layers, the temperature of which is 
shown by the thermometer, are still below that tempera- 
ture. A good quality of burning oil should not flash below 
110° P. 



CHAPTER XLV. 

EXAMINATION OF ILLUMINATING GAS. 

The tests most frequently made or required in deter- 
mining the value of illuminating gas are : Specific grav- 
ity, illuminating power, sulphur and ammonia. 

The Specific Gravity may be determined by Bunsen's 
method of weighing a glass globe when exhausted by an 
air-pump, when filled with air, and when filled with 
the gas, and from the data obtained calculating the re- 
sult. The more convenient and more common method 
at present in gas-testing stations is the Schilling effusion 
test, in which the times of effusion of equal volumes of 
gas and air through a fine hole in a thin, metallic plate 
are compared. The principle upon which it depends 
being that the specific gravities of two gasses passing 
through such an opening are proportionate to the squares 
of the times of effusion. As the specific gravity of ail 
is taken as 1.000, if a given volume of air escapes in 139 
seconds, and the same volume of gas requires but 90 sec- 
onds, the calculation would be : 

Sp. gr. of air (= 1) : Sp. gr. of gas = (139* =) 19,321 
: (90 2 =) 8,100 
Sp. gr. of gas = £«» = 0.419 

Illuminating Power. — The methods most relied upon 
in taking the illuminating power depend upon the princi- 
ple that the intensity of light varies inversely as the 
square of the distance from its source. If, then, between 
two lights which are to be compared we place a light 
screen and move it back and forth until both sides are 
equally illuminated, its respective distances from the two 
lights will be as 1 to 1 if they are equal in intensity ; as 1 
to 4 if one is twice as bright as the other ; as 1 to 9 if one 
is thrice as bright, and so on. 



246 EXAMINATION OF ILLUMINATING GAg. 

If one of these lights is assumed as a standard, we 
have then a measure of the illuminating power of the 
other in terms of the standard. 

The Standard adopted is the light derived from a sperm 
candle, of which six weigh one pound, and each of which 
will burn 120 grains per hour. These candles are manu- 
factured at present expressly for this purpose. When 
cast in the moulds they are made slightly tapering from 
the butt in order to facilitate their removal when cooled. 
This taper should be removed by drawing them through 
a plate like a wire-drawing plate, that they may be uni- 
form in calibre. This process is sometimes neglected by the 
manufacturer, so that each candle should be examined 
before using to see that it is of uniform diameter through- 
out. If the candle — as is frequently the case — does not 
burn exactly 120 grains per hour, a correction may be 
made for the variation, provided it does not exceed 6 grains 
on either side of this rate,?', e., is between 114 and 126 
grains. If those limits are exceeded the results should be 
rejected. 

The Burner for the gas was originally required by 
British acts of Parliament to be " an argand burner hav- 
ing 15 holes and a 7-inch chimney. " This description 
was, however, not found to be sufficiently close, as a large 
variety of burners might answer this description, and 
give very different results with the same gas. 

A pattern, however, answering this description was man- 
ufactured, and for a long time both here and in England 
known as the ' l Standard London argand. ' ' More recently, 
however, the question of standards for gas has been 
overhauled in England, and standard burners manufac- 
tured by Sugg, of London, have been adopted, of which 
the material dimensions of the various parts, &c. , are accu- 
rately specified. It is sufficient here to state that for gas 
of under 20 candle power the burner known as "Sugg's 
London argand 'No. 1 " is used. This is provided with a 
steatite (commonly called lava) chamber with 24 holes, 



PHOTOMETRY — METER. 247 

aud a chimney of 6 inches in height, and an internal 
diameter of 1| inches. For gas of nnder 16 candle-power 
a chimney of If inches internal diameter, and of the same 
height, is nsed with the same burner. For cannel gas and 
other rich gases, a steatite bats wing burner is used. In 
this country for gas running up to 30 candle power 
another burner manufactured by Sugg, and similar to his 
' ' London argand No. 1, ' is used, which is provided with 32 
holes and a 9-inch chimey. 

Meters. — The rate at which the gas is to be burned is 5 ft. 
per hour. As the duration of a test is ordinarily not over 
i5 minutes, an experimental meter registering to thou- 
sandths of a foot is necessary. A wet meter is used in 
which the water is brought to a given level indicated by 
a mark on the gauge. In some photometric rooms a 
clock striking every minute with a preliminary alarm 5 
seconds before it strikes is used ; but the most recently 
constructed meters for this purpose are provided with a 
hand run by clock work, which will travel around the 
face of the meter with the meter hand, if the gas burns at 
exactly the rate of 5 ft. per hour, while if it does not, the 
amount by which the one hand is in advance of the other 
furnishes a basis for a simple calculation of the rate per 
hour for which a correction must be made, in calculating 
the candle power. 

Photometer Bar and Disc. — The photometer bar is sim- 
ply the bar on which the disc is moved back and forth 
between the two lights, and is graduated so that by the 
aid of a pointer immediately below the disc the candle 
power observed may be at once read off. The lights are 
usually placed at 100 inches apart. The disc formerly 
used was of paper stretched in a small circular frame, 
oiled except a small spot in the centre. The form at pres- 
ent used is a paper with a star-shaped hole in the centre 
between two thin plain papers, the whole set in a frame, 
and inclosed in a box blackened inside to exclude reflec- 



248 EXAMINATION OF ILLUMINATING- GAS. 

tions, and prevent the glare of the lights which are com- 
pared from distracting the attention. 

Pressure, etc. — The pressure at the meter should be 
equal to half an inch of water, and at the burner should be 
as nearly zero as possible. Attention is not always given to 
the barometric pressure, and the temperature of the room 
in which the tests are made. The barometer should stand 
at 30 inches, and the temperature should be 60° F. If 
any great variation from these figures occurs, corrections 
should be made to obtain the true measurement of the gas 
passed through the meter. 

The Photometer Room should have the walls, ceiling 
and floors, colored dead black to avoid reflections, which 
would interfere with the correctness of the observations. 

In making the test the candle should be first lighted 
and allowed to burn for five or ten minutes ; the gas also 
should be allowed to burn for about the same length of 
time, and the rate of burning adjusted with a tangent screw- 
cock. The candle (or candles, since two are now often 
used) are counterbalanced by the use of shot or sand, and 
at the same instant the time is noted. With the most im- 
proved forms of apparatus, the candles are balanced and 
weighed in position. With some other forms, the balance 
is separate from the rest of the apparatus, and provided 
with a socket at one end of the beam to receive the candle. 
The disc is then moved back and forth on the bar until 
both sides appear to be equally illuminated, and the read- 
ing is taken once and sometimes twice a minute. The 
meter is also observed every minute to insure uniformity 
of burning of the gas. These readings are of course 
recorded as fast as made, and after ten or fifteen minutes 
an average is taken ; the amount of candle burned is ascer- 
tained by adding grain weights to the pan under the can- 
dle socket to replace the weight burned, and the time 
noted. In this way the candle and gas rates are obtained ; 
the photometer readings are averaged, and where two can- 
dles have been used, the figure obtained is doubled. This 



CANDLE POWEE — SULPHUR. 249 

gives observed candle power, which must be corrected for 
both gas and candle rates. 

Correction for Gas and Candle. — If the gas has burned 
at the rate of over 5 feet per hour, the observed candle power 
is too high ; if the gas rate is less than 5 feet it is too low. 
We therefore correct by a proportion : 

Gas rate : 5 ft. = obs. c. p. : c. p. corrected for gas. 

This result must again be corrected for candle rate by a 
similar proportion. If the candle rate is over 120 grains, 
the reading has been too low ; if under 120 grains, it is too 
high. The proportion therefore is : 120 : candle rate =* 
c. p. : corrected candle power. These corrections may be 
made in either order, when, if the arithmetic is correct, 
the result will be essentially the same. E. g.\ Suppose 
the observed candle power to be 17.12, the gas rate 4.9, 
the candle rate 124 grains : 

In correcting first for e;as rate, 

4.9 : 5 = 17.12 : candle power corrected = 17.46. 

Correcting this for candle rate, 

120 : 124 = 17.46 : correct candle power = 18.04. 

Or, to correct first for candle rate, 

120 : 124 == 17.12 : candle power corrected == 17.69. 

Then, for gas rate, 

4.9 : 5 = 17.69 : correct candle power = 18.05. 

Essentially the same result. 

Sulphur. — This is determined in gas by burning the 
gas slowly in such a way that the products of combustion 
mingle with fumes of ammonia or its carbonate, collect- 
ing the ammonia compounds of the sulphur thus obtained 
(sulphate and sulphite), oxidizing them to sulphate, and 
determining as usual by precipitation with barium chloride. 
An experiment meter registering to thousandths of a 
foot is used, and from four to ten feet of gas are burned 
for a determination, at the rate of from half a foot to 
one foot per hour. Two forms of apparatus are used, 
"Letheby's" and "the Referee's." In the first (which 
is the older form) the gas is burned in a Leslie burner, 



250 EXAMINATION OF ILLUMINATING GAS. 

which consists of a number of small metal tubes, 
arranged in a ring like an argand burner. Below the 
burner is placed a beaker containing ammonia, over which 
a funnel is inverted, the stem of the funnel coming up 
through the centre of the burner. Over the burner is a 
trumpet tube, in shape like a long truncated cone, the 
upper end of which is turned at right angles and passes 
through a cork in a horizontal, cylindrical " receiver," 
shaped like a double-ended bottle, with a shoulder at 
each end. In the receiver is also placed about 20 c. c. of 
strong ammonia. To the other end of the receiver is fitted 
a long tube, about the size of combustion tubing. This 
tube is not set quite horizontal, but inclined slightly up- 
ward so that any liquids condensing in it will flow back 
to the receiver. It is often also surrounded by a Liebig 
condenser, to insure more complete condensation. 

In the Ref eree' s apparatus the gas is burned in a single 
hole steatite jet, around which are placed lumps of am- 
monium sesquicarbonate, while over it is placed a trumpet 
tube, as in the Letheby apparatus. Instead of the " re- 
ceiver," however, a tall, glass bubbling- jar is used, filled 
with marbles, over which a stream of ammonia is made to 
trickle slowly. The ammonia flows through a tube at 
the bottom into a beaker placed to receive it. To insure 
sufficient draught through the marbles it is sometimes 
well to attach an aspirator to the upper end of the bub- 
bling- jar, and keep up an exhaustion of about one quar- 
ter to one half an inch of water. 

With either apparatus, after a sufficient amount of gas 
has been burned ; the entire apparatus, trumpet tube and 
all, are thoroughly washed out ; the washings and con- 
tents of the receiver, etc., added together; the whole 
evaporated nearly or quite to dryness, a few c. c. of bromine 
water added and again evaporated, and finally water 
added to bring the solution up to a convenient bulk, and 
the sulphate precipitated as usual with barium chloride. 

The sulphur calculated from the weight of barium sul- 



AMMONIA. 251 

phate thus obtained is reckoned to so and so many grains 
per hundred feet of gas, and is so reported. The amount 
depends on the character of the materials used in making 
the gas, and the kind and efficiency of the methods of 
purification used. The amount depending upon these 
conditions may be from five to over forty grains per 100 
feet. 

Ammonia is usually determined by passing several feet 
of the gas (measured by an experiment meter) slowly 
through a measured quantity of half normal sulphuric 
acid, and then by titration determining the amount of sul- 
phuric acid which has been neutralized. A Peligot bulb 
tube, or a tube filled with marbles wetted with the sulphuric 
acid solution, may be used for the purpose — indeed, any 
method which permits the intimate contact of the gas 
with solution, and subsequent removal of the solution 
for titration. The ammonia (ETH S ) is calculated like the 
sulphur to grains per 100 ft. The amount found is usu- 
ally in the neighborhood of two to three grains, though 
in certain cases it may run much higher. 



CHAPTER XLVI. 

SOAP. 

A good hard soap should not contain less than 54 per 
cent of fat acids, combined with at least one eighth that 
amonnt of soda (Na 2 0), and not over 40 per cent of water. 

In the analysis of soap, we may have to determine 
(1) combined fatty acids, (2) unsaponified fat, (3) resin, 
(4) glycerine, (5) combined alkali (Na a O), (6) uncombined 
alkali (NaHO), (7) free carbonate (JS r a 2 C0 3 ), (8) chloride, 
trace, (9) sulphate (Na 2 S0 4 ), (10) foreign matter, which 
may include impurities or adulterants, as clay, sand, 
ochre, talc, sodium silicate, etc., and (11) water. 

Analysis. 

Dissolve 5 gms of the soap in fine shavings in 80 or 90 
c. c. of 90 per cent alcohol, heating it on the water-bath 
until solution is effected. 

The solution will then contain the first six constituents 
above-mentioned, together with the water, while the resi- 
due will contain the other constituents. 

Solution. — Pass a current of carbon dioxide through it 
for some time. The uncombined alkali will be converted 
into NaHC0 3 , and will precipitate. Filter, wash with alco- 
hol, dissolve in water, and titre with half -normal sulphu- 
ric acid. (Alkalimetry p. 207. ) Calculate to NaHO for 
(6) uncombined alkali. 

To the filtrate or the alcoholic solution in which C0 2 failed 
to produce a precipitate, add 15 or 20 c. c. of water, and 
evaporate off the alcohol. Add 25 or 30 c. c. of half- 
normal sulphuric acid from a burette, and a weighed 
quantity (5 gms.) of pure white wax, boil, filter through 
a wetted filter, and wash with boiling water until the 
washings are no longer acid. Cool the cake of wax which 
takes up the fat acids and resin, dry between bibulous 



TJNCOMBINED FAT — RESIN. 263 

paper, and weigh. The weight, less the weight of the 
wax added, gives that of (1) combined fatty acids, (2) un- 
combined fat, and (3) resin. 

In the filtrate from the wax, etc., determine by means 
of a half -normal soda solution, how much of the sulphuric 
acid used has been neutralized by the alkali of the soap, 
the result gives (5) combined alkali. Calculate to Na 2 0. 

Residue. — Dry and weigh, treat with water, and filter, 
dry again and weigh. The last weight is that of the (10) 
foreign matter insoluble in water. Titre the water solu- 
tion with half -normal sulphuric acid. Calculate the re- 
sult to Na 2 C0 3 . This gives (7) free carbonate. The first 
weight, less the foreign matter insoluble in water, and also 
less free carbonate, gives the weight of neutral salts sol- 
uble in water. 

(2) UneomMned Fat. — Treat 5 gms. of the soap (cut 
into very fine shavings) with ether two or three times, 
pouring off the ether into a weighed dish The operation 
may be assisted by placing the vessel over a water-bath 
containing hot water, but with no flame under it. Since 
the ether may dissolve small portions of the soap, it 
is safer to evaporate off the ether from the first extrac- 
tion, and then to treat the residue again with ether. 
The weight of the residue left on the last evaporation of 
the ether gives (2) unsaponified fat. Carbon disulphide 
may be used in place of ether. 

(3) Resin. — Dissolve 40 gms. of the soap in boiling 
water, add an excess of sulphuric acid to separate the 
fatty acids and resin, cool, pour off the aqueous portion, 
and digest the fatty residue with equal volumes of alcohol 
and water, agitating from time to time. Pour off the 
milky fluid, add more alcohol and water, and digest again. 
Repeat this until the fluid ceases to become milky, then 
add water and a weighed quantity of wax as before, 
filter, dry, and weigh the cake. The weight represents 
that of the fatty acids deprived of the resin. The differ- 
ence of percentage obtained in this way from the percent- 



254 soap. 

age obtained as before described, gives approximately the 
amount of the resin present. 

(4) Glycerine. — Dissolve 5 gms. of the soap in 90 per 
cent alcohol, add dilute alcoholic sulphuric acid (1 vol. 
concentrated sulphuric acid to 10 vols, alcohol) so long 
as a precipitate forms, filter, wash with alcohol, digest 
with barium carbonate and water until the alcohol is gone, 
filter, evaporate the filtrate to dryness in a weighed dish 
at gentle heat, and weigh the residue of glycerine. 

(5, 6, 7, 8, 9, and 10) Mineral Constituents. — Calcine 5 
gms., weigh, dissolve in water, filter. Residue is (10) 
foreign matter. Dilute the solution to some convenient bulk 
(say 200 c. c). In one half, determine total alkali (5, 6, and 
7) by titration with half -normal sulphuric acid. A portion 
may be taken to test for the presence of potassium salts. 
In one quarter, determine (8) chloride, by titration with 
standard solution of silver nitrate, with potassium chro- 
mate as indicator. In the remaining quarter, determine 
(9) sulphate, by precipitation with barium chloride, as 
usual. Calculate chloride and sulphate to ISTaCl and 

(11) Water. — Some analysts determine all the other 
constituents, and calculate the remainder as water. It 
may, however, be determined by dissolving 1 or 2 gms. in as 
little strong alcohol as possible, pouring the solution upon 
a weighed quantity of sand in a dish, and drying in the 
air-bath at 110° C. to constant weight. The loss represents 
the water. 



CHAPTER XLVII. 

FLOUR. 

Digest 5 gms. of the flour in 100 c. c. cold water for 
one or two hours, with frequent stirring, filter through a 
filter previously exhausted with hydrochloric acid, washed, 
dried, and weighed, wash with about 100 c. c. cold water. 
The solution contains (1) albumen, (2) gum, (3) sugar, and 
a portion of the soluble salts. The residue contains (4) 
cellulose, (5) starch, gluten, and fat. 

Solution. — 1. Boil, and then filter ; the precipitate con- 
sists of albumen. Dry at 100° C, and weigh. 

[Note. — The treatment with water, filtration and pre- 
cipitation of albumen should be completed on the same 
day. By keeping the solution hot it may be continued 
through two days, but this is not advisable.] 

2. Evaporate the filtrate from the albumen nearly to 
dryness, add a large excess of alcohol, warm, and then 
allow it to cool, filter on a weighed filter, wash with alco- 
hol. Dry at 100° C, and weigh the gum thus obtained. 

3. Evaporate the alcoholic filtrate from the gum to small 
bulk, add water, and boil out the alcohol. Concentrate 
the solution to 50 c. c, and divide in halves. In 
the first half, determine the glucose direct by the 
copper sulphate solution as described under Raw Sugar 
(p. 225). In the second half, add a few drops of dilute 
sulphuric acid, boil, neutralize with potassium hydrate, 
and determine glucose by copper sulphate as before. The 
excess of glucose found in the second determination is due 
to cane sugar. 

Residue. — Wash with a jet from the wash-bottle into a 
beaker. Then dry the filter with what adheres to it, and 
weigh. This weight, less that of the filter found at the 
beginning, gives the weight of adhering substance, which 



256 FLOUR. 

must be taken into account in the subsequent determina- 
tions. 

4. Add to the substance in the beaker, 50 times its 
weight of water containing one per cent of sulphuric acid, 
and heat for several hours, until the starch goes into solu- 
tion, and only light floculent cellulose is left. Filter and 
wash until all sulphuric acid is removed, dry at 100° C, 
and weigh. 

5. To the filtrate from the cellulose, diluted to 400 c. c, 
add about 30 c. c. concentrated sulphuric acid, and heat 
on a water-bath at about 95° C. for several hours, adding 
water from time to time to keep it up to the original bulk. 
Digest thus until a drop of the solution shows no colora- 
tion when treated with diluted iodine solution, and also 
gives no precipitate with alcohol. When the conversion 
of the starch into glucose is complete, neutralize the excess 
of acid by sodium or potassium hydrate and determine the 
glucose with copper sulphate as before. 

The starch can also be determined in a separate portion, 
by washing a weighed quantity with water, then with 
ether, and again with water, drying and then making an 
elementary analysis for carbon (see elementary analysis of 
sugar), or with copper oxide and lead chromate. The 
carbon found is from both starch and cellulose. Deduct 
the carbon due to cellulose found as above (formula, 
C 12 H 10 O 10 the same as that of starch), and calculate the rest 
to stai(h (44 parts carbon = 100 parts starch). 

Albumenoids. — Determine the total nitrogen in 1 gm. 
by combustion with soda-lime (guano, p. 222), and from 
this calculate the albumenoids ; 15.5 parts N ' = 100 parts 
albumenoids. From this deduct the albumen found as 
above ; the difference is gluten. 

Fat. — Weigh out 2 or 3 gms. of the flour, treat with 
ether, boiling it gently over the water-bath, decant the 
ether through a filter into a weighed dish, repeat this two 
or three times, evaporate off the ether, and weigh the fat. 

Ash. — Burn 40 or 50 gms. of the flour in a weighed dish. 



ASH — WATER. 25? 

If therb is any difficulty in burning off the carbon, cool 
and weigh the dish and contents ; then extract with hot 
water, filter through a small filter, avoiding any transfer of 
the carbonaceous substance to the filter. Dry the dish, 
and weigh again. The loss represents mineral salts dis- 
solved out. Moisten with nitric acid, add the filter-paper 
and contents, and burn again, cool, and weigh. The 
weight, less that of the dish, represents the remain- 
der of the ash. The weight of the ash of the small filter- 
paper may be ignored. The ash may be dissolved in 
water with a little nitric acid, and analyzed as required. 

Water.— Dry 1 or 2 gms. in the air-bath at 110 to 120° 
C. to constant weight. Loss = water. 

All filter-papers used in this analysis, on which different 
constituents (albumen, gum, etc.) are weighed, should be 
prepared by soaking for about half an hour in dilute 
hydrochloric acid (1 : 10) washing thoroughly with water, 
and drying. 



TABLES. 



TABLES OF WEIGHTS A1STD MEASURES. 



The following comparison of French, weights and meas- 
ures with those of the United States have been taken or 
calculated from similar tables given by Br. Warren De la 
Rue. Ure's Dictionary, III., p. 1119. 

Slight discrepancies from other authorities exist, e. g., 
the gramme is given by De la Rue as equivalent to 15.4323 
grains. The U. S. Dispensatory, 13th Ed., pp. 1734 and 
1735, gives 15.434 grains, and refers to other authorities 
which give 15.444 grains as the equivalent of the gramme. 

The number of grains in the U. S. gallon of 231 cubic 
inches is here taken as 58,318, which is believed to be cor- 
rect, from a calculation based upon results obtained from 
experimental researches on the expansion of liquids, and a 
reference to the English standard for the wine or Win- 
chester gallon, on which it is based. (See note of W. H. 
Chandler, Am. Chem. I., 318.) The U. S. Dispensatory 
(ib.) gives 58,328.886 grains. 

The report of F. R. Hassler, of the coast survey, gives 
58,372.1754 in 1832, and in 1842 Hassler makes it 58,373 
grains. The reasons for considering this erroneous will be 
found in Barnard's Metric System, jx 158. 



262 TABLES. 



MEASURES OF CAPACITY 


(U. S. PHARMACOPEIA). 








Grains <rf 


Cubic 


Gal. Qts. Pts. Fl. oz. 


Fl. dr. Minims. 


water at 62° F. 


centimetres. 


1 = 4 = 8 = 128 = 


: 1,024 = 61,440 


= 58,318.00 = 


= 3,785.200 


1 2 32 


256 15,380 


14,579.50 


946.300 


1 16 


128 7,690 


7,289.75 


473.150 


1 


8 480 


455.61 


29.570 




1 60 


56.95 


3.690 




1 


0.95 


0.061 


1 English Imperial gallon 


= 277.274 cu. in. 


70,000.00 


4,543.000 


1 " " pint 


= 34.659 " 


8,750.00 


568.000 


Other English gallons : 








1 wine c= Winchester gal. 


= 231.000 " 


58,318.00 


3,785.200 


1 corn gallon, 


268.800 " 


67,861.00 


4,402.900 


lale 


282.000 «? 


71,193.40 


4,619.200 


leu. ft. = 283.15c. c. 








1 cu. in. = 16.38 c. c. 


0.061027 cu. in. = 1 c. c. 






LINEAR MEASURES. 








Metre. 






Metre. 


i yard 

1 foot ........ 


. . 0.91438 
.. 0.30480 


1 inch. .. 




0.0254 


39.3708 inch ah 


.... 1.0000 




TROY WEIGHT. 






Lb. Oz. Dwt. Grs. 






Grammes. 


1 = 12 = 240 = 5,760 






.. 373.2419 


1 20 480. .... 






... 31.1035 


1 24 






1.5552 


1 






. . 0.0648 



AVOIRDUPOIS WEIGHT. 

ton. Cwt. Qr. St. Lbs, Kilogrammes. 

1 = 20 = 80 = 160 = 2,240 1,016.00 

14 8 112 . 50.80 

1 2 28 12.70 

1 14 6.35 

Oz. Dr. Grs. Troy. Grammes. 

1 = 16 = 256 = 7,000.00 453.5926 

1 16 437.50 28.3495 

1 27.34 1.7718 

1 net ton = 2,000 lbs 907 kilogrammes. 

apothecaries' weight. 

Lb. Oz. Dr. Scruples. Grains. Grammes. 

1 = 12 = 96 = 288 = 5,760.. 373.2419 

11 8 24 480 31.1035 

31 3 60 3.8879 

31 20 1.2960 

0.0022 lb. Av. = 0.03527 oz. Av. = 15.4323 grs 1 gm. 

Lbs. Av. Grammes. 

1 cu. ft. water at 62° F. = 62.3550 28,315.0000 

lcu.in. *< " " 0.0361 16.38C 

— Watts's Dictionary, V., 1010. 



TABLE OF ATOMIC WEIGHTS. 



Revised by C. F, CHANDLER and F, G, WIECHMANN,! 



OCTOBER, 1881. 



Aluminium, 


Al. 


IV. 


27 


1 Manganese, 


Mn. 


VI. 


55 


Antimony, 


Sb. 


V. 


120-0 


! Mercury, 


Hg. 


II. 


200 


Arsenic, 


As. 


V. 


74 "9 


Molybdenum, 


Mo. 


VI. 


96 


Barium, 


Ba. 


II. 


136 8 


Mckel, 


m. 


VI. 


59 


Bismuth, 


Bi. 


V. 


2100 


Nitrogen, 


N. 


V. 


14 


Boron, 


B. 


III. 


110 


Osmium, 


Os. 11 


. IV. 


199 


Bromine, 


Br. 


I. 


79-7 


Oxygen, 


O. 


II. 


16-0 


Cadmium, 


Cd. 


II. 


1120 


Palladium, 


Pd. 


IV. 


106 


Caesium, 


Cs. 


I. 


133 


j Phosphorus, 


P. 


V. 


31 


Calcium, 


Ca. 


II. 


40 


Platinum, 


Pt. 


IV. 


197 


Carbon, 


C. 


IV. 


12 


| Potassium, 


K. 


I. 


39 


Cerium, 


Ce. 


III. 


1412 


J Rhodium, 


Ro. 


IV. 


104 


Chlorine, 


CI. 


I. 


35 4 


i Rubidium, 


Kb. 


I. 


85 


Chromium, 


Cr. 


VI. 


52 4 


Ruthenium, 


Ru. II. IV. 


104 


Cobalt, 


Co. 


VI. 


59 


Selenium, 


Se. 


II. 


79 


Columbiwm, 


Cb. 


V. 


94 


Silicon, 


Si. 


IV. 


280 


Copper, 


Cu. 


II. 


631 


Silver, 


Ag. 


I. 


108 


Davyum, 


Da. 




154 


Sodium, 


Na. 


I. 


23 


Didymium, 


D. 


III. 


147 


Strontium, 


Sr. 


II. 


87 5 


Erbium, 


E. 


III. 


169 


Sulphur, 


S. 


II. 


32 


Fluorine, 


F. 


I. 


19-0 


Tantalum, 


Ta. 


V. 


182-0 


Gallium, 


Ga. 


III. 


69 9 


Tellurium, 


Te. 


II. 


128 


Grlucinum, 


Gl. 


II. 


9 2 


Thallium, 


27. 


I. 


204 


Gold, 


Au. 


III. 


196 2 


Thorium, 


Th. 


IV. 


231-5 


Hydrogen, 


H. 


I. 


10 


Tin, 


Sn. 


TV. 


1180 


Indium, 


In. 


III. 


113 4 


Titanium, 


Ti. 


IV. 


50 


Iodine, 


I. 


I. 


126 5 


Tungsten, 


W. IV. VI. 


184 


Iridium, 


Ir. 


II. 


198-0 


Uranium, 


U. 


VI. 


240 


Iron, 


Fe. 


VI. 


56 


Vanadium, 


V. 


V. 


51 -S 


Lanthanum, 


La. 


[III. 


139 


Yttrium, 


Y. 


III. 


600 


Lead, 
Lithium, 


Pb. 


n. 


207 


Zinc, 


Zn. 


II. 


65 


Li. 


i. 


7 


Zirconium, 


Zr. 


IV. 


900 


Magnesium, 


Mg. 


ii. 1 


24 


1 









Note. — The Artiads are printed in Roman, the Perissads in 
Italics. 



264 



TABLES. 



TABLE OF SPECIFIC GRAVITIES CORRESPONDING WITH DEGREES BEAU ME FOR 
LIQUIDS LIGHTEtt THAN WATER. 

The following is taken from the United States Dispensatory (Wood and 
Bache). In that volume three different values are given for the value of 
degrees Beaume in specific gravities. Those which follow were from the 
French Codex : 



Deg. 


Specific 


Deg. 


Specific 


Deg. 


j Specific 


Deg. 


Specific 


B. 


gravity. 


B. 


gravity. 


B. 


gravity. 


B. 


gravity. 


10.. . 


1.000 


27... 


0.894 


44... 


0.809 


61... 


0.738 


11.. . 


0.993 


28... 


0.889 


45... 


0.804 


62... 


0.735 


12.. . 


0.986 


29... 


0.883 


46... 


0.800 


63... 


0.731 


13.. . 


0.979 


30... 


0.878 


47... 


0.795 


64... 


0.727 


14.. . 


0.973 


31... 


0.872 


48... 


0.791 


65... 


0.724 


15.. . 


0.966 


32... 


0.867 


49... 


0.787 


66... 


0.720 


16. . 


0.960 


33... 


0.862 


50... 


0.783 


67... 


0.716 


17.. . 


0.953 


34... 


0.857 


51... 


0.778 


68. . . 


0.713 


18.. . 


0.947 


35... 


0.852 


52... 


0.774 


69... 


0.709 


19.. . 


0.941 


36... 


0.847 


53... 


0.770 


70... 


0.706 


20.. . 


0.935 


37... 


0.842 


54... 


0.766 


71... 


0.702 


21.. . 


0.^29 


38... 


0.837 


55... 


0.762 


72. . . 


0.699 


22.. . 


0.923 


39... 


0.832 


56... 


0.758 


73. . . 


0.696 


23.. . 


0.917 


40... 


0.827 


57... 


0.754 


! 74. . . 


0.692 


24.. . 


0.911 


41... 


0.823 


58... 


0.750 


75... 


0.689 


25.. . 


0.905 


42... 


0.818 


59... 


0.746 


I 76... 


0.686 


26.. . 


0.900 


43... 


0.813 


60... 


0.742 


'77... 


0.682 



The specific gravity may be calculated from the formula : 

144 



Sp. gr. = 



B 



134. 



For specific gravities corresponding with degrees B. for liquids heavier 
than water, see Table of values of Sulphurie acid. 



TABLES. 



266 



TABLE OF VALUES OF SULPHURIC ACID. 

A. H. Elliott, Proc. Am. Chem. Soc, II., p. 26, adopted by Manufac- 
turing Chemists' Assoc. See Dingier, CCLX., 268. Tables taken from 
Kolbe & Rosensdtiehl's results. Bulletin de la Soc. Ind. de Mulhouse y July 
and August, 1872, pp. 209 and 238. 



Degrees Beaume. 


Specific 
gravity. 


Per cent 
H 2 S0 4 . 


Degrees Beaume. 


Specific 
gravity. 


Per c'nt 
H a S0 4 . 


1... 


1.005 
1.011 
1.023 
1.029 
1.036 
1.043 
1.050 
1.057 
1.064 
1.071 
1.086 
1.093 
1.100 
1.107 
1.114 
1.122 
1.136 
1.143 
1.150 
1.158 
1.172 
1.179 
1.186 
1.201 
1.208 
1.216 
1.231 
1.238 
1.254 
1.262 
1.269 
1.285 
1.293 


0.93 

1.87 

3.74 

4.67 

5.61 

6.54 

7.48 

8.41 

9.35 

10.28 

12.15 

13.09 

14.02 

14.96 

15.89 

16.83 

18.70 

19.63 

20.57 

21.50 

23.37 

24.31 

25.24 

27.11 

28.05 

29.98 

30.85 

31.79 

33.66 

34.59 

35.53 

37.40 

38.33 


34 


1.309 
1.317 
1.334 
1.342 
1.359 
1.368 
1.386 
1.395 
1.413 
1.422 
1.441 
1.451 
1.470 
1.480 
1.500 
1.510 
1.531 
1.541 
1.562 
1.573 
1.594 
1.616 
1.627 
1.650 
1.661 
1.683 
1.705 
1.727 
1.747 
1.767 
1.793 
1.814 
1.835 


40.20 


2 


35 

36 


41.14 


3 


43.01 


4 


37 


43.94 


5 


38 


45.81 


6 


39 


46.75 


7 


40 


48.62 


8 


41.. 


49.55 


9 


42. 


51.42 


10 


43 

44 


52.36 


11 


54.23 


12 


45 


55.16 


13 


46 


57.03 


14 


47 


57.97 


15 


48 

49 


59.84 


16 


60.77 


17 


50 

51 


62.64 


18 


63.58 


19 


52 


65.45 


20 


53 


66.38 


21 


54 


68.25 


22 


55 


70.12 


23 


56 


71.06 


24 


57 


72.93 


25 


58. 


73.86 


26 


59.. 


75.7a 


27 


60 


77.60 


28 


61.. 


79.47 


29 


62 


81.34 


30 


63 


83.21 


31 


64 


86.02 


32 


65 


88.82 


33 


66 


93.50 







266 



TABLES- 



TABLE OF SPECIFIC GRAVITY OF SOLUTIONS OF HYDROCHLORIC ACID. TEMP., 

15° (URE). 



Specific 


Per cent 


Specific 


Per cent 


Specific 


Per cent 


gravity. 


HC1. 


gravity. 


HC1. 


gravity. 


HC1. 


1.2000 


40.777 


1.1328 


26.913 


1.0637 


13.048 


1.1982 


40.369 


1.1308 


26.505 


1.0617 


12.641 


1.1964 


39.961 


1.1287 


26.098 


1.0597 


12.233 


1.1946 


39.554 


1.1267 


25.690 


1.0577 


11.825 


1.1928 


39.146 


1.1247 


25.282 


1.0557 


11.418 


1.1910 


38.738 


1.1226 


24.874 


1.0537 


11.010 


1.1893 


38.330 


1.1206 


24.466 


1.0517 


10.602 


1.1875 


37.923 


1.1185 


24.058 


1.0497 


10.194 


1.1857 


37.516 


1.1164 


23.650 


1.0477 


9.786 


1.1846 


37.108 


1.1143 


23.242 


1.0457 


9.379 


1.1822 


36.700 


1.1123 


22.834 


1.0437 


8.971 


1.1802 


36.292 


1.1102 


22.426 


1.0417 


8.563 


1.1782 


35.884 


1.1082 


22.019 


1.0397 


8.155 


1.1762 


35.476 


1.1061 


21.611 


1.0377 


7.747 


1.1741 


35.068 


1.1041 


21 . 203 


1.0357 


7.340 


1.1721 


34.660 


1.1020 


20.796 


1.0337 


6.932 


1.1701 


34.252 


1.1000 


20.388 


1.0318 


6.524 


1.1681 


33.845 


1.0980 


19.980 


1.0298 


6.116 


1.1661 


33.437 


1.0960 


19.572 


1.0279 


5.709 


1.1641 


33.029 


1.0939 


19.165 


1.0259 


5.301 


1.1620 


32.621 


1.0919 


18.757 


1.0239 


4.893 


1.1599 


32.213 


1.0899 


18.349 


1.0220 


4.486 


1.1578 


31.805 


1.0879 


17.941 


1.0200 


4.078 


1.1557 


31.398 


1.0857 


17.534 


1.0180 


3.670 


1.1537 


30.990 


1.0838 


17.126 


1.0160 


3.262 


1.1515 


30.582 


1.0818 


16.718 


1.0140 


2.854 


1.1494 


30.174 


1.0798 


16.310 


1.0120 


2.447 


1.1472 


29.767 


1.0778 


15.902 


1.0100 


2.039 


1.1452 


29.359 


1.0758 


15.494 


1.0080 


1.631 


1.1431 


28.951 


1.0738 


15.087 


1.0060 


1.124 


1.1410 


28.544 


1.0718 


14.679 


1.0040 


0.816 


1.1389 


28.136 


1.0697 


14.271 


1.0020 


0.408 


1.1369 


27.728 


1.0677 


13.863 






1.1349 


27.321 


1.0657 


13.456 







TABJ.KS. 



267 



TABLE SHOWING THE AMOUNT OF NITRIC ACID (HNO s ) CONTAINED IN SOLU- 
TIONS OF DIFFERENT SPECIFIC GRAVITIES. TEMP., 15° (URE). 



HN0 3 


| Specific 


HNO3 


Specific 


hno 3 


Specific 


per cent. 


| gravity. 


per cent. 


gravity . 


per cent. 


gravity. 


100 


i 1.5000 


: 66 


1.3783 


33 


1.1895 


99 


1.4980 


65 


1.3732 


32 


1.1833 


98 


1.4960 


64 


1.3681 


31 


1.1770 


97 


1.4940 


63 


1.3630 


30 


1.1709 


93 


1.4910 


62 


1.3579 


29 


1.1648 


95 


1.4880 


61.. 


1.3529 


28 


1.1587 


94 


1.4850 


60 


1.3477 


27 


1.1526 


93 


1.4820 


59 


1.3427 


26 


1.1465 


92 


1.4790 


58 


1.3376 


25 


1.1403 


91 


1.4760 
1.4730 
1.4700 


57 

56 

1 55 


1.3323 
1 . 3270 
1.3216 


24 

23 

22 


1.1345 


90 


1.1286 


89 


1 . 1227 


88 


1.4670 


54 


1.3163 


21 


1.1168 


87 


1.4640 


53 


1.3110 


20 


1.1109 


86 


1.4600 


52 


1.3056 


19 


1 . 1051 


85 


1.4570 


51 


1.3001 


18 


1.0993 


84 


1.4530 


50 


1.2947 


17 


1.0935 


83 


1.4500 


49 


1.2887 


16 


1.0878 


82 


1.4460 


48 


1.2826 


15 


1.0821 


81 


1.4424 


47 


1.2765 


14 


1.0764 


80 


1.4385 


46 


1.2705 


13 


1.0708 


79 


1.4346 
1.4306 


45 


1.2644 
1.2583 


12 

11 


1.0651 


78 


44 


1.0595 


77 


1.4269 


43 


1.2523 


10 


1.0540 


76 


1.4228 


42 


1.2462 


9 


1.0485 


75 


1.4189 


41 


1.2402 


8. . 


1.0430 


74 


1.4147 


40 


1.2341 


t 


1.0375 


73 


1.4107 


39 


1.2277 


6 


1.0320 


72 


1.4065 


38 


1.2212 


5 


1.0267 


71 


1.4023 


37 


1.2148 


4 


1.0212 


70 


1.3978 


36 


1.2084 


3 ! 


1.0159 


69 


1.3945 


35 


1.2019 


2... 


1.0106 


68 


1.3882 
1.3833 


34 


1.1958 


1 | 


1.0053 


67 





268 



TABLES. 



TABLE OF SPECIFIC GRAVITY OF SOLUTIONS OF CRYSTALLIZED TARTARIC 
ACID IN WATER. TEMP., 15°. WATER AT 15° = 1. 





Gerlach, " 


Specifische Gewichte deb Salzlosungen." 




Per cent. 


Specific 


Per cent. 


Specific 


Per cent. 


Specific 




gravity. 




gravity. 




gravicy. 


1 


1.00450 


20 


1.09693 


39 


1.20190 


2 


1.00900 


21 


1.10200 


40 


1.20785 


3 


1.01360 


22 


1.10720 


41 


1.21380 


4 


1.01790 


23 


1.11240 


42 


1.21980 


5 


1.02240 


24 


1.11750 


43 


1.22590 


6 


1.02730 


25 


1.12270 


44 


1.23170 


7 


1.03220 


26 


1.12820 


45 


1.23770 


8 


1.03710 


27 


1.13380 


46 


1.24410 


9 


1.04200 


28 


1.13930 


47 


1.25040 


10 


1.04692 


29 


1.14490 


48. 


1.25680 


11 


1.05170 


30 


1.15047 


49 


1.26320 


12 


1.05650 


31 


1.15600 


50 


1.26962 


13 


1.06130 


32 


1.16150 


51 


1.27620 


14 


1.06620 


33 


1.16700 


52 


1.28280 


15 


1.07090 


34 


1.17260 


53 


1.28940 


16 


1.07610 


35 


1.17810 


54 


1.29610 


17 


1.08130 


36 


1.18400 


55 


1.30270 


18 


1.08650 


37 


1.19000 


56 


1.30930 


19 


1.09170 


38 


1.19590 


57 


1.31590 



1ABLE OF SPECIFIC GRAVITY OF SOLUTIONS OF CRYSTALLIZED CITRIC ACID 
IN WATER. TEMP., 15°. WATER AT 15° = 1. 

Gerlach, "Specifische Gewichte der Salzlosungen." 

















Specific 




Specific 




Specific 


Per cent. 


gravity. 


Per cent. 


gravity. 


Per cent. 


gravity. 


1 


1.00370 


23 


1.09300 


45 


1.19470 


2 


1.00740 


24 


1.09720 


46 


1.19980 


3 


1.01110 


25 


1.10140 


47 


1.205C0 


4 


1.01490 


26 


1.10600 


48 


1.21030 


5 


1.01860 


27 


1.11060 


49 


1.21530 


6 


1.02270 


28 


1.11520 


50 


1.22041 


7 


1.02680 


29 


1.11980 


51 


1.22570 


8 


1.03090 


30 


1.12439 


52 


1. 23"70 


9.... 


1.03500 


31 


1.12880 


53 


1.23590 


10........ 


1.03916 


32 


1.13330 


54 


1.24100 


11 


1.04310 


33 


1.13780 


55 


1.24620 


12 


1.04700 


34 


1.14220 


56 


1.25140 


13 


1.05090 


35 


1.14670 


57 


1.25720 


14 


1.05490 


36 


1.15150 


58 


1.26270 


15 


1.05880 


37 


1.15640 


59 


1.26830 


16 


1.06320 


38 


1.16120 


60 


1.27382 


17 


1.06750 


39 


1.16610 


61 


1.27940 


18 


1.07180 


40 


1.17093 


j 62.. 


1.28490 


19 


1.07620 


41 


1.17560 


63 


1.29040 


20 


1.08052 


42 


1.18140 


64 


1.29600 


21 


1.08480 


43 


1.18510 


65 


1.30150 


22 


1.08890 1 


44 


1.18990 


66 


1.30710 



TABLES. 



269 



TABLE OF SPECIFIC GRAVITY OF SOLUTIONS OF ACETIC ACID. TEMP. 15" 



C 3 H 4 
2 per 
cent. 


Specific 
gravity. 


C 2 H 4 
2 per 
cent. 


Specific 
gravity. 


C 2 H 4 
2 per 
cent. 


Specific 
gravity. 


C 2 H 4 
2 per 
cent. 


Specific 
gravity. 


0... 


1.0000 


26.. 


1.0363 


51.. 


1.0623 


76.. 


1.0747 


1... 


1.0007 


27.. 


1.0375 


52.. 


1.0631 


77.. 


1.0748 


2... 


1.0022 


28.. 


1.0388 


53.. 


1.0638 


78.. 


1.0748 


3... 


1.0037 


29.. 


1.0400 


54.. 


1.0646 


79.. 


1.0748 


4... 


1.0052 


30.. 


1.0412 


55.. 


1.0653 


80.. 


1.0748 


5... 


1.0067 


31.. 


1.0424 


58.. 


1.0660 


81.. 


1.0747 


6... 


1.0083 


32.. 


1.0436 


57.. 


1.0666 


82.. 


1.0746 


7... 


1.0098 


33.. 


1.0447 


58.. 


1.0673 


83.. 


1.0744 


8... 


1.0113 


34.. 


1.0459 


59.. 


1.0679 


84.. 


1.0742 


9... 


1.0127 


35.. 


1.0470 


60.. 


1.0685 


85-. 


1.0739 


10... 


1.0142 


36.. 


1.0481 


61.. 


1.0691 


86 . 


1.0736 


11... 


1.0157 


37.. 


1.0492 


62.. 


1.0697 


87 . 


1.0731 


12... 


1.0171 


38.. 


1.0502 


63.. 


1.0702 


88.. 


1.0726 


13... 


1.0185 


39.. 


1.0513 


64.. 


1.0707 


89.. 


1.0720 


14... 


1.0201 


40.. 


1.0523 


65.. 


1.0712 


90.. 


1.0713 


15... 


1.0214 


41.. 


1.0533 


66.. 


1.0717 


91.. 


1.0705 


16... 


1.0228 


42.. 


1.0543 


67.. 


1.0721 


92.. 


1.0696 


17... 


1.0242 


43.. 


1.0552 


68.. 


1.0725 


93.. 


1.0686 


18... 


1.0256 


44.. 


1.0562 


69.. 


1.0729 


94.. 


1.0674 


19... 


1.0270 


45.. 


1.0571 


70. . 


1.0733 


95.. 


1.0660 


20... 


1.0284 


46.. 


1.0580 


71.. 


1.0737 


96.. 


1.0641 


21 .. 


1.0298 


47.. 


1.0589 


72.. 


1.0740 


97.. 


1.0625 


22... 


1.0311 


48.. 


1.0598 


73.. 


1.0742 


98.. 


1.0604 


23... 


1.0324 


49.. 


1.0607 


74.. 


1.0744 


99.. 


1.0580 


24... 


1.0337 


50.. 


1.0615 


75.. 


1.0746 


100.. 


1.0553 


25. . . 


1.0350 















TABLE SHOWING THE PERCENTAGE OF AMMONIA (NHs) CONTAINED IN 
SOLUTIONS OF DIFFERENT SPECIFIC GRAVITIES. TEMP., 14° (CARIUS). 





Am- 




Am- 




Am- 




Am- 


Specific 


monia, 


Specific 


monia, 


Specific 


monia, 


Specific 


monia, 


gravity. 


per 


gravity. 


per 


gravity. 


per 


gravity. 


per 




cent. | 




cent. 




cent. 




cent. 


0.8844 


36 


0.9052 


27 


0.9314 


18 


0.9631 


9 


0.8864 


35 ' 


0.9078 


26 


0.9347 


17 


; 0.9670 


8 


0.8885 


34 


1 0.9106 


25 


0.9380 


16 


0.9709 


7 


0.8907 


33 


0.9133 


24 


0.9414 


15 


0.9749 


6 


0.8929 


32 


0.9162 


23 


0.9449 


14 


0.9790 


5 


0.8953 


31 


0.9191 


22 


0.9484 


13 


0.9831 


4 


0.8976 


30 ! 


0.9221 


21 


0.9520 


12 


! 0.9873 


3 


0.9001 


29 ! 


0.9251 


20 


0.9556 


11 


0.9915 


2 


0.902<? 


28 , 


0.9283 


19 


0.9593 


10 


0.9959 


1 



270 



TABLES. 



TABLE SHOWING THE AMOUNT OF K a O IN POTASS A LYE OF DIFFERENT 
SPECIFIC GRAVITIES. TEMP., 17.5°. 





Hoffman, Schaedler, "Tabellen fur Chemiker " p. 


119. 




K 2 




K 2 




K 2 




K 2 




per 


Specific 


per 


Specific 


per 


Specific 


per 


Specific 


cent. 


gravity. 


cent. 


gravitj . 


cent. 


gravity. 


cent. 
12. 


gravity. 


45. 


1.576 


34. 


1.414 


23. 


1.209 


1.135 


44.5 


1.568 


33.5 


1.407 


22.5 


1.263 


11.5 


1.129 


44. 


1.560 


33. 


1.400 


22. 


1.257 ' 


11. 


1.123 


43.5 


1.553 


32.5 


1.393 


21.5 


1.250 


10.5 


1.117 


43. 


1.545 


32. 


1.886 


21. 


1.244 : 


10. 


1.111 


42.5 


1.537 


31.5 


1.879 


20.5 


1.238 i 


9.5 


1.105 


42. 


1.530 


31. 


1.372 


20. 


1.231 


9. 


1.099 


41.5 


1.522 


30.5 


1.365 


19.5 


1.225 1 


8.5 


1.094 


41. 


1.514 


30. 


1.358 


19. 


1.219 | 


8. 


1.088 


40.5 


1.507 


29.5 


1.852 


18.5 


1.213 


7.5 


1.082 


40. 


1.500 


29. 


1.345 


18. 


1.207 | 


7. 


1.076 


39.5 


1.492 


28.5 


1.339 


17.5 


1.201 


6.5 


1.070 


39. 


1.484 


28. 


1.332 


17. 


1.195 1 


6. 


1.065 


38.5 


1.477 


27.5 


1.326 


16.5 


1.189 


5.5 


1.059 


38. 


1.470 


27. 


1.320 


16. 


1.183 


5. 


1.054 


37.5 


1.463 


26.5 


1.313 


15.5 


1.177 


4.5 


1.048 


37. 


1.456 


26. 


1.307 


15. 


1.171 


4. 


1.042 


36.5 


1.449 


25.5 


1.301 


14.5 


1.165 


3.5 


1.037 


36. 


1.442 


25. 


1.294 


14. 


1.159 


3. 


1.031 


35.5 


1.435 


24.5 


1.288 


13.5 


1.153 


2.5 


1.026 


35. 


1.428 


24. 


1.282 


13. 


1.147 


2. 


1.021 


34.5 


1.421 


23.5 


1.275 


12.5 


1.141 J 


1.5 


1.015 



TABLE SHOWING THE SODIUM OXIDE (Na 2 0) IN SODA LYES OF DIFFERENT 
SPECIFIC GRAVITIES. TEMP., 17.5°. 



Hoffman-Schaedler, "Tabellen fur Chemiker." 



Na 2 
per 
cent. 



Na 2 




Na 2 




per 


Specific | 


per 


Specific 


cent. 


gravity. ; 


cent. 


gravity. 

i 


35. 


1.500 


27.5 


1.389 


34.5 


1.492 


27. 


1.382 


34. 


1.485 


26.5 


1.375 


33.5 


1.477 


26. 


1.367 


33. 


1.470 


25.5 


1.360 


32.5 


1.463 


25. 


1.353 


32. 


1.455 


24.5 


1.345 


31.5 


1.448 


24. 


1.338 


31. 


1.440 


23.5 


1.331 


30.5 


1.433 


23. 


1.324 


30. 


1.426 


22.5 


1.317 


29.5 


1.418 


22. 


1.309 


29. 


1.411 


21.5 


1.302 


28.5 


1.404 


31. 


1.295 


28. 


1.396 


20.5 


1.288 



20. 

19.5 

19. 

18.5 

18. 

17.5 

17. 

16.5 

16. 

15.5 

15. 

14.5 

14. 

13.5 

13. 





Na 2 


Specific 


per 


gravity. 


cenv. 


1.281 


12.5 


1.274 


12. 


1.2 6 


11.5 


1.259 


11. 


1.252 


10.5 


1.245 


10. 


1.238 


9.5 


1.231 


9. 


1.224 


8.5 


1.217 


8. 


1.210 


7.5 


1.203 


7. 


1.195 


6.5 


1.188 


6. 


1.181 


5.5 



Specific 
gravity. 



1.174 
1.167 
1.160 
1.153 
1.146 
1.139 
1.132 
1.125 
1.118 
1.111 
1.104 
1.097 
1.090 
1.083 
1.076 



TABLES. 



271 



TABLE OF SPECIFIC GRAVITY OF SOLUTIONS OF SODIUM CHLORIDE AT 15° 
WATER AT 15° = 1. 



Gerlach, "Specifische Gewichte der Salzlosungen. 



Per cent. 


Specific gravity. 


Per cent. 


Specific gravity. 


1 


1.00725 
1.01450 
1.02174 
1.02899 
1.03624 
1.04366 
1.05108 
1.05851 
1.06593 
1.07335 
1.08097 
1.08859 
1.09622 


I 14 


1.10384 


2 


15 


1.11146 


3 


16 


1.11938 


4 


17 


1.12730 


5 


18 


1.13523 


6 


19 


1.14315 


7 


20 


1.15107 


8 


21 


1.15931 


9 


22 


1.16755 


10 


23 


1.17580 


11 


24 


1.18404 


12 . 


25 


1.19228 


13.. 


26 


1.20098 









TABLE SHOWING THE PERCENTAGE OF AMMONIUM CHLORIDE IN SOLUTIONS 
OF DIFFERENT SPECIFIC GRAVITIES. TEMP., 15°. WATER AT 15° = 1„ 

Gerlach, "Specifische Gewichte der Salzlosungen." 



Per cent. 


Specific gravity. 


Per cent. 

t 


Specific gravity. 


1 ,o 

2 Q0 


1.00316 
1.00632 
1.00948 
1.01264 
1.01580 
1.01880 
1.02180 
1.02481 
1.02781 
1.03081 
1.03370 
1.0365S 
1.0394? 

: 


14 

15 


1.04325 
1.04524 


3 


16 


1.04805 


4 


17 


1.05086 


5 


18 


1.05367 


6 


19 


1.05648 


7 


20 


1.05929 


8. 


21 


1.06204 


9 


22 


1.06479 


10 


23 

24 .. 

25 


1.06754 


11 


1.07029 


12 


1.07304 


13 


26 


1.07375 









INDEX. 



Page. 
Absorption, Determination of Carbonic 

Acid by 24, 25 

Absorption, Determination of Water by . . 38 

Acetic Acid (Reagent) 33 

in Lime Acetate 221 

Strength of (Table) 269 

Acetate of Lime, Analysis 221 

Acidimetry and Alkalimetry 207 

Albumen in Flour 255 

Albuminoid Ammonia 179, 180 

Albuminoids in Flour 248 

Alkalies. (See also Potassium, Sodium, 
Ammonium. ) 

Alkalies in Bone-Black ?. 236 

in Clay 68 

" in Feldspar 53 

in Iron Ore 97 

in Limestone 66 

inSlag 101 

" in Superphosphate 202 

Uncombined in Soap 252 

in Water 176 

Alkalimetry and Acidimetry 207 

Alkaline Metals in Cast-Iron, etc 118 

Alum, Ammonia Iron (Anal.) 40 

Potassium (Analysis) 26 

Alumina (Determination) 26 

InClay 67 

" in Feldspar 52 

" in Iron Ore 93, 94 

*• etc., in Mineral Water 185 

•' in Paint 170 

•' inSlag 101 

" in Water 174 

Alumina and Ferric Oxide in Limestone ... 60 
" " " in Manganese 

Ore 70 

Aluminum in Cast-Iron, etc 117 

Ammonia, Free and Albuminoid 179, 180 

in Iron Ammonia Alum 47 

in Gas 251 

in Guano 223 

in Superphosphate 202 

Iron Alum (Sulphate ) ( Anal. ). . . . 40 
Ammonium Carbonate (Reagent) 11.27, 32, 144 
Copper Sulphate, Kiefer's So- 
lution 75 

Chloride (Reagent) 53 

Strength of (Table). . 271 

" Hydrate (Reagent) 11, 26 

Strength of (Table). . 269 
u Magnesium Phosphate 17 



Page. 

Ammonium Oxalate (Reagent) 11, 21 

Phospho Molybdate 81, 83 

" Solution (Water Analysis) . . . 179 

Anhydride, Phosphoric. (See Phosphoric 
Acid.) 
Sulphuric. (See Sulphuric 
Acid.; 

Antimony in Cast-iron, etc 118 

in Copper Ore 137 

in Refined Lead 158 et seq. 

in Type Metal 154 

• " Ore (Analysis) 152 

" Tetroxide (Sb 3 4 ) 153 

Apothecaries' Weight 262 

Apparatus for Carbonic Acid Determina- 
tion 22, 25 

Argentic. (See also Silver.) 

Nitrate (Reagent) 11, 14 

Arsenic in Cast Iron, etc 118 

" in Copper Ore 137 

" in Iron Ore 97 

in Refined Lead 158 et seq. 

in Type Metal 154 

Ore (Analysis) 149 

Arsenious Acid Solution (Volumetric) 218 

Ash. (See also Mineral Matter.) 

in Flour 256 

in Milk 205 

in Raw Sugar 229 

in Superphosphates 202 

Atomic Weights (Table) 263 

Available Chlorine 219 

" Oxygen 72 

Avoirdupois Weight 262 

B 

Barium Carbonate in Paint 168 

" Chloride (Analysis) 12 

" (Reagent) 18 

inBaCla 12 

in Cast-iron, etc 102 

in Limestone 64 

in Mineral Water 189 

" Sulphate in Paint 168 

Sulphate (Precipitate) 12, 18 

Barytes in Paint 169 

Beakers 8 

Beaume and Specific Gravity (Tables). 264, 265 

Bismuth in Refined Lead 160 et seq. 

Bleaching Powder 219 et seq. 

Bone-Black Analysis 234 

Boracic Acid in Mineral Water 190 

Bromide, Potassium (Anal.) 35 



274 



]T^DEX. 



Page. 

Bromine (Determination) 35 

in Mineral Water 191 

" Water (Reagent) ?I 

Bronze (Analysis) 147 

Burner, Standard 246 

Burning Point of Oil 244 

•« Oil in Petroleum 243 

Butter in Milk 204 

c 

Cadmium in Refined Lead 160 et seq. 

Calcium. (See also Lime.) 

" in Calcium Carbonate 31 

" in Cast-iron, etc 117 

Carbonate (Analysis) 21 

(Reagent) 53 

Chloride (Reagent) 32, 39 

Chloride Solution "Hardness". 177 

" Fluoride (Analysis). 31 

Oxalate (Precipitate) 21 

Sulphate (Precipitate) 21 

" Sulphate in Paint 168, 170 

Calculation Acetate of Lime 222 

" Bicarbonate of Soda 216 

" Bleaching Powder 219 

" Manganese Oxides "76 

" Mineral Waters 193 

Water Analysis 182 

Candle, Standard 246 

Carbon Combined, in Cast-Iron, etc 108 

" Colorimetric 108 

Dioxide. (See Carbonic Acid.) 

Fixed.inCoal 238 

inSugar 231 

in Turpentine 233 

" Total, in Cast-iron, etc 104 

Carbonate Ammonium (Reagent) — 11, 27, 32 

" Calcium, Analysis 21 

" (Reagent) 53 

Barium, in Paint 168 

" Basic Lead in Paint 170 

" in Manganese Ore 73 

" Sodium (crude) 212 

" " (Reagent) 32 

" " Bi- (Analysis) 215 

" "in Alkalimetry 207 

" " in Mineral Water 185 

in Soap 253 

" " Solution, Water Anal. . 179 

Carbonic Acid by Direct Weight 24 

" by Loss 22 

"in Bicarbonate of Soda 215 

" in Bone-Black. 234 

" in Iron Ore 97 

" in Limestone 62 

" in Mineral Water 187 

Casein in Milk 205 

Cast-Iron (Analysis) 102 

Cellulose in Flour 256 

Chlorhydric Acid. (See Hydrochloric Acid.) 

Chloride Ammonium (Reagent) 53 

" Barium (Analysis) 12 



Page. 

Chloride Barium (Reagent) 18 

Calcium (Reagent) 32, 39 

" Solution, "Hardness"... 177 

Potassium Platino 28, 30 

Silver, Precipitate 14 

Sodium 37 

" Strength of (Table) 271 

Chlorimetry 218- 

Chlorine Available 219 

' ' Effect on Permanganate 48- 

inBaCl 2 • 13 

in Bicarbonate of Soda 216- 

in Bone-Black 236 

" in Iron Ore 97 

" in Limestone 65 

" in Mineral Water 187 

"' in Soap 254 

in Superphosphate 201 

" in Water 175 

" Water (Reagent) 35 

" Volumetric Determination. . .175, 218 
Chromate, Bi-, Potassium, Volumetric So- 
lution. 46 

Chromium in Cast-Iron, etc 117 

" in Iron Ore 89 

Citric Acid, Strength of (Table) 268 

Clay, Analysis Grav. , and Mechanical 67 

" in Paint 168 

Coal Analysis 238 

Cobalt and Nickel, Electrolytic Det 131 

" " Separation... 128 etseq., 134 

in Cast-Lron, etc 117 

" in Iron Ore 96 

" in Refined Lead 159 et seq. 

Cochineal Indicator. 211 

Combined Carbon In Cast-Iron, etc. (Color- 
imetric) 108 

Combustible, Volatile, in Coal 238 

Completeness of Burning and Washing 

Bone-Black 237 

Copper- Ammonium Sulphate (Kiefer's So- 
lution) 75 

Copper, Determination as Cu 2 S 133 

CuO 138 

Electrolytic Determination 136 

Potassium Tartrate 228 

in Bronze 147 

" in Cast-Iron, etc 118 

in German Silver 140 

inlronOre 97 

in Refined Lead 160 et seq. 

" OreAnalysis 136 

Coralline Indicator 211 

Crucibles & 

Cubic Foot. Weight of, Bone-Black 23*5 

D 

Decolorizing Power of BoneBlacic 237 

Delivery Mark of Flasks 4 

Distillation, Fractional 242 

Distilled Water, Water Analysis 180 

Dittmar's Flux 85 



INDEX. 



275 



Page. 

Electrolytic Det. of Cobalt and Nickel. ... 131 

Copper 136 

Elementary Analysis of Sugar 231 

" Turpentine 233 

F 

Fat in Milk 204 

" in Flour 256 

" Uncombined in Soap 253 

Fatty Acids in Soap 252 

Feldspar Analysis 49 

Ferric Compounds. (See Iron.) 

Ferric Ammonio Sulpliate (Anal.) 40 

Ferrous Compounds. (See Iron.) 
Ferrocyanide Potassium, Volumetric Solu- 
tion 125 

Filtering 8 

Filter for Carbon in Iron and Steel 105 

Papers in Flour Analysis 257 

Fineness of Bone-Black 236 

Fixed Carbon in Coal 238 

Flashing Point of Oil 244 

Flasks, Measuring, Standardizing 3 

Flour Analysis 255 

Fluoride, Calcium (.Analysis) 31 

ofSilicon 31 

Potass ' um Silico 32 

Fluorine (Determination) 31, 32 

in Iron Ore 97 

" in Limestone 66 

Formula for Sp. Gr. and Degrees Be 264 

Fractional Distillation 242 

Free and Albuminoid Ammonia 179, 180 

French and United States Weights and 

Measures (Tables) 262 

Fusion 49, 85 

" Dittmar's Flux 85 

Hart's Method 79, 95 

" Smith's Method 53 

G 

Galena Analysis 142 

Gallon, U. S 174, 183 

Gas, Illuminating, Examination 245 

" Ammonia in 251 

" Photometry 245 

" Specific Gravity 245 

" Sulphur in 249 

German Silver Analysis 140 

Glucose, Artificial, in Raw Sugar 230 

in Raw Sugar 223 

Glycerine in Soap C54 

Grains in Gallon, Mgs. in Litre 1S3 

Graphite in Cast-Iron, etc 112 

Guano Analysis 223 

Gum in Flour 255 

H 

" Hardness " of Water 176 

' "Permanent" and "Tempo- 
rary" 178 

Heating Power of CoaL 240 



Page. 

Holding Mark of Flasks 3 

Hydrate, Ammonium (Reagent) 11, 26 

Strength of (Table). . 269 

Potassium (Normal) 208 

" " or Sodium, Strength 

of (Table) 270 

Hydrochloric Acid 34 

" " for Decomposing Man- 
ganese Ore 75 

" Normal 211 

" Strength of (Table) 266 

Hydro-Disodium Phosphate (Analysis) 36 

(Reagent) 18 

Hydrogen in Sugar 231 

in Turpentine 233 

Hydrometer Beaume Deg. (Tables) 264 

I 

Ignition 9 

Illuminating Gas 245 

Indicators, Alkalimetry, etc 210 

Introduction 1 

Inverting Sugar 227 

Iodide Palladium 34 

" Potassium (Analysis) 34 

Iodine (Determination) 34 

in Mineral Water 191 

Iodized Starch Paper 218 

Iron Ammonia Alum (Sulphate) (Anal.) 40 

" Cast and Wrought ( Analysis) 1 02 

" and Alumina in Limestone 6<> 

" and Alumina in Manganese Ore 70 

" and Alumina, etc., in Mineral 

Water 185, 189 

" by Ignition 41 

" by Precipitation 40 

' ' by Volumetric Determination 41, 46 

" inBone-Black 236 

•' in Bronze 148 

" in Cast-iron, etc 102 

" in Clay 67 

" in Feldspar 52 

" in German Silver 141 

" in Iron Ammonia Alum 41 

" inlronOre 79, 84 

" in Refined Lead 159 et seq. 

" in Slag 101 

" in Tin Ore 146 

" in Type Metal 154, 156 

" in Water 174 

' ' Method for Available Oxygen 73 

" " for Bleaching Powder 220 

" Ore, Complete Analysis 86 

" Containing neither Titanium nor 

Chromi m 98 

" " Containing Titanium and no 

Chromium 98 

" " Partial Analysis 78 

)' Volumetric Determination 41, 46 

Wire Stt 43 



276 



INDJCX. 



Page. 

K 

Kiefers Solution 75 

Kroonig Valve 42 

L 

Lead Carbonate Basic in Paint 170 

Lead in Bronze 117 

in Galena 143 

in Type Metal 154 

Oxide in Paint 172 

Refined (Analysis) 157 

Sulphate in Paint 168, 170 

Letheby Sulphur Apparatus 249 

Lime Acetate (Analysis) 221 

in Clay 67 

in Feldspar B3 

in Iron Ore 95 

in Limestone 80 

etc., in Mineral Water 185 

in Slag 101 

in Water 174 

Soda- (Reagent) 24 

Lime, Superphosphate (Analysis) 197 

Limestone Analysis 59 

Linear Measures 262 

Lithium in Feldspar 57 

in Mineral Water 190 

Litmus Indicator 211 

Litre, Milligms. in, Grains in Gallon 183 

Logwood Indicator 211 

M 

Magnesia Determination 17 

In Cast-iron, etc 117 

in Clay 67 

in Feldspar 53 

In Iron Ore 95 

in Limestone 61 

in Mineral Water 185 

in Blag 102 

in Water 174 

Mixture 11, 37 

Magnesium Ammonium Phosphate 17 

Magnesium Pyro- Arsenate, Purifying 150 

" Pyrophosphate 17, 38 

Sulphate Analysis 17 

Mtinganate Per-, Volumetric Solution 41 

Manganese in Cast-iron, etc 117 

" in Clay 68 

" in Limestone 64 

" in Iron Ore 94 

in Slag 101 

in Mineral Water 189 

in Refined Lead 159 et seq. 

" Ore Analysis 70 

Oxides, Calculating 76 

Silicate 72 

Marguerite's Volumetric Determination of 

Iron 41 

Measures and Weights, United States and 

French (Tables) 262 

Measuring 2 



Page. 

Mercuric Oxide (Reagent) 128 

Mercurous, Nitrate tReagent) 126 

Meter, Gas 247 

Milk Analysis 204 

" Standard. . 206 

Milligrammes in Litre and Grains in Gal- 
lon 183 

Mineral Matter. (See also Ash.) 

" in Guano 225 

inMilk 205 

inSoap 254 

Mineral Water Analysis 184 

Moisture. (See Water.) 

Molybdate Phospho Ammonium 81, 83 

Molybdate Solution 11 

Molybdenum in Cast-Iron, etc 120 

N 

Naphtha In Petroleum 243 

Nessler's Solution 179 

Nickel and Cobalt, Electrolytic Determi- 
nation 131,135 

Nickel and Cobalt, Separation 128, 134 

" in Cast-iron, etc 117 

in German Silver 140 

in Iron Ore 96 

in Refined Lead 159 et aeq. 

Ore Analysis . 127 

Nitrate Argentic (Reagent)- II, 14 

" Mercurous (Reagent) 128 

Silver Volumetric Solution 175 

Nitrates in Water 181 

NitricAcid 85 

"in Mineral Water 191 

" Strength of (Table) ....267 

Nitrate Potassium (Reagent) 129 

Nitrogen in Bone-Black 236 

" In Cast-iron, etc 119 

Normal and Half Normal Solutions 207 

Note Books 9 

Notes on Coal 239 

o 

Oil, Burning, in Petroleum 243 

" Flashing and Burning Point 244 

" in Paint 168 

Oils, Parafflne, in Petroleum 243 

Organic and Volatile Matter in Water 173 

" Matter in Feldspar 57 

" in Iron Ore 97 

" " in Limestone 63 

Oxalate Ammonium (Reagent) 11, 21 

Calcium 21 

" Potassium (Reagent) 72 

Oxalic Acid, Half Normal 212 

" " (Reagent) 43 

Oxide Di-, Carbon. (See Carbonic Acid.) 

" Mercuric (Reagent) 128 

" Manganese Calculation 76 

" Titanic, in Iron Ore 91 

Oxygen Available 72 

" " Iron Method 73 

" " Pattinson's Method 74 



INDEX. 



277 



Page. 

P 

Paint Analysis 167 

Palladium Chlor de (Reagent) 34, 192 

Palladium Iodide 34 

Palladium, Metalli j 34 

ParaffineOils in Petroleum 243 

Permanganate Potassium (Reagent) 42 

" " test on Water, 

178, 180 

Petroleum Analysis 242 

Phosphate Hydro-Disodium (Analysis) 86 

" " " (Reagent) 17 

" Magnesium Ammonium 17 

" " Pyro-(Reagent)....17,38 

Phospho Molybdate Ammonium 81, 83 

Phosphoric Acid in Bone-Black 234 

" in Guano 223 

" " in Hydro-Disodium Phos- 
phate 37 

«' " inlronOre 80,93 

" " in Limestone 62 

" " in Magnesium Pyro-Arse- 

nate 150 

" in Mineral Water 189 

" " inSlag 101 

" " (Insoluble) in Superphos- 
phate 199 

" " (Precipitated) in Super- 
phosphate 199 

" •' (Soluble) in Superphos- 
phate 198 

" Volumetric Det 200 

" Anhydride. (See Phosphoric 

Acid.) 

Phosphorus in Cast-iron, etc 114 

Photometer, etc 247 

Pipettes, Graduating, etc 4 

Platino Chloride, Potassium 28, 30 

PlatinumFoil 45 

"(Spongy) 29 

M " Tetrachloride Reagent 11, 28 

Plumbic Compounds . (See Lead . ) 

Polarizing Sugar 226 

Porosity of Bone-Black 237 

Potable Water Analysis 173 

Potassium. (See also Alkalies.) 

" Alum (Analysis) 26 

" Bromide (Analysis) 35 

Bichromate Volumetric Solu- 
tion 46 

" Copper Tartrate 228 

(Determination) 27, 30 

" Ferrocyanide Volumetric So- 
lution 125 

Hydrate (Normal) 208 

" " Strength of (Table).. 270 

in Feldspar 53 

" in Mineral Water 186 

" in Water 176 

•• Iodide (Analysis) 34 

H Nitrate (Reagent) 129 



Page. 

Potassium Oxalate (Reagent) 72 

" Permanganate (Reagent) 42 

" " Test on Water, 

178, 180 

Silico Fluoride 32 

Bisulphate 87 

Power, Heating, of Coal 240 

Pressure in Gas Testing 248 

Q 

Quartz Sand in Clay 6* 

R 

Raw Sugar (Analysis) 226 

Reagents, Excessive use of 1 

MakingUp 10 

" Valueoflc. c 11 

Referee's Sulphur Apparatus 249 

Report on Coal 239 

" on Guano • • . 225 

" on Petroleum 243 

" on Superphosphate 203 

Resin in Soap 253 

Rochelle Salt (Reagent) 228- 

s 

Saccharimeter 226 

Sal Ammoniac 53 

Salts (See also Ash and Mineral Matter.) 

SaltsinMilk 205 

Saratoga Waters, Analysis of 194 

Scheibler's C0 2 Apparatus 234 

Silica 31,32 

" inClay 57 

" in Feldspar 51 

•' inlronOre 79,88 

" in Limestone 60 

" in Mineral Water 185 

" in Paint. . 168 

" in Slag 101 

" in Tin Ore 146 

" in Water 174 

Silicates in Clay 68 

Silico Fluoride Potassium 32 

Silicon Fluoride.. 31 

in Cast-iron, etc 102, 114 

Silver Chloride (Precipitate) 14 

" in Galena 143, 144 

'• in Refined Lead 157 

•' Nitrate (Reagent) 11, 14 

" " Volumetric Solution 1 75 

Slag Analysis 100 

" in Cast-Iron, etc 121 

Smith, J . L . , Method of Det . Alkalies 53 

Soap Analysis 252 

Solution for " Hardness " 177 

Solids, Total in Mineral Water 184 

Solvents 2 

Soda Ash (Analysis), Alkalimetry. . 212 

" Bicarbonate Analysis 215 

Soda Lime (Reagent) 24 

Sodium Carbonate (Crude) 212 

" " (Reagent) 32 



278 



INDEX. 



Page. 

Sodium Cai bonate (Reagent) in Alkalimetry 207 

in Water Anal. 179 

" " in Mineral Water 185 

" Chloride 37 

" Strength of (Table) 271 

Hydrate, Strength of (Table) 270 

" Hydro-Di-, Phosphate (Analysis) 36 

(Reagent).... 17 

" in Bicarbonate of Soda 216 

" in Feldspar 53 

' ' in Hydro-Disodium Phosphate 36 

in Water 176 

Sulphite (Reagent) 82 

" Sulpho Stannate 145 

Specific Gravity and Beaume (Tables) 264 

" of Gas 245 

Starch in Flour 256 

" Paper Iodized 218 

Standard in Milk 206 

Standardizing Alkalimetric.etc, Solutions 209 

Flasks 3 

" Potassium Permanganate.. 42 

Stannate, Sulpho-Sodium 145 

Stannic Compounds. (See also Tin.) 

" Oxlde(Bronze) 147 

Steel Analysis 102 

Strontium in Limestone 64 

" in Mineral Water 189 

Sugar in Flour 247 

" in Milk 206 

" Inverted 827 

" Raw(Analysis) 226 

" Ultimate Analysis 231 

Sulphate Aluminum Potassium (Analysis). 26 
" Ammonio Copper, Kief er's Solu- 
tion 75 

" Ammonio Ferric (Anal.) 40 

Barium 12, 18 

" in Paint 168 

Calcium (Precipitate) 21 

in Paint 168.170 

" in Soap 254 

" in Sodium Bicarbonate 216 

Leadin Paint 168,170 

" Magnesium Analysis 17 

Potassium Acid (Reagent) 87 

Sulphite Sodium (Reagent). 82 

Sulpho-Stannate, Sodium 145 

Sulphuric Acid (Reagent) 11 

" Half Normal 207 

" " in Guano 224 

" inMgSO*.... 18 

" in Mineral Water 185 

" "in Superphosphate 202 

" in Water 175 

" Strength of (Table) 265 

" Anhydrite. (See Sulphuric Acid.) 
Sulphur Compounds in Mineral Waters. . . 195 

In Coal 238 

" In Cast-Iron, etc 114,116 

" In Galena 144 



Page. 

Sulphur in Gas 249 

in Iron Ore 80, 96 

" in Limestone 96 

in Refined Lead 165 

" Waters (Analysis) 194 

Superphosphate of Lime (Analysis) 197 

T 

Table for Calculating Water Analyses 183 

Table for Scheibler's Apparatus 235 

Tables of Weights and Measures 258 

Tartaric Acid, Strength of (Table) 268 

Tin in Bronze 147 

" in Cast-Iron, etc 118 

" in Refined Lead. . 158 et seq. 

" in Type Metal 155 

" Ore Analysis 145 

Titanium in Cast-Iron, etc 102 

" inClay 67 

" inlronOre 85,91, 92 

Titration. (See Volumetric.) 

Total Solids in Mineral Water 184 

TroyWeight 262 

Tungsten in Iron Ores 100 

Turpentine, Ultimate Analysis 233 

Type Metal Analysis 154 

u 

Ultimate Analysis of Coal 240 

" of Sugar 231 

" " of Turpentine 233 

Uranium Solution, Volumetric 201 

United States and French Weights and 
Measures (Tables) 262 

V 

Valve, Kroonig 42 

Vanadium in Cast-Iron, etc 120 

" in Iron Ores 99 

Vinegar Analysis 213 

Volatile and Organic Matter in Water 173 

Combustible in Coal 238 

Volumetric Determination of Chlorine 175 

Volumetric Determination of Chlorine in 

Chlorides 2J8 

Volumetric Determination of Iron 41 

Volumetric Determination of Phosphoric 

Acid 201 

Volumetric Determination of Zinc 125 

Volume of Coal, Weight of 239 

w 

Water Chlorine (Reagent) 35 

Water Determination, Direct, by Absorp- 
tion 38 

Water Determination by Loss 16, 19, 30 

" Distilled for Water Analysis 180 

" Fresh, or Potable Analysis 173 

" " Hardness" of 176 

in Barium Chloride, etc 16, 19, 30 

" in Clay 67 

in Coal 38 

" in Feldspar 57 

" in Flour. 267 



INDEX. 



279 



Page. 

Water in Guano 224 

" in Iron Ore 97 

" in Limestone 63 

" in Milk 204 

in Raw Suear 229 

" in Soap 254 

" in Sodium Bicarbonate 215,216 

" in Superphosphate of Lime 202 

" Mineral (Analysis) 184 

Waters, Saratoga 194 

Sulphur 194 

Washing 8 

Weighing 5 

Weights and Measures, United States and 
French (Tables) 254 



Page. 

Welter's Law 241 

Witherite in Paint 168 

Wrought-Iron Analysis 102 



Zinc, Amalgamated 45 

" in Bronze 148 

" in Cast-Iron, etc 117 

" in German Silver 140 

" in Iron Ore 96 

" in Nickel Ores 134 

in Refined Lead 159 et seq. 

" Oxide in Paint 170 

" OreAnalysis 123 

" Volumetric Determination 125 




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